- 1Collaborative Innovation Center of Assessment for Basic Education Quality, Beijing Normal University, Beijing, China
- 2School of Psychology, Northwest Normal University, Lanzhou, China
- 3Faculty of Humanities and Social Sciences, City University of Macau, Macau, China
- 4Mental Health Education Center, Yunnan College of Business Management, Kunming, Yunnan, China
- 5School of Psychology, Shenzhen University, Shenzhen, China
- 6The Shenzhen Humanities and Social Sciences Key Research Bases of the Center for Mental Health, Shenzhen University, Shenzhen, China
Objective: Internet addiction and depressive symptoms are common mental health problems in adolescents. Due to the comorbidity of Internet addiction and depressive symptoms, their mutual relationship influences their developmental trajectories over time. Thus, this study aimed to identify the joint trajectories of Internet addiction and depressive symptoms, and examined the individual, family, and school antecedents of these trajectories among Chinese adolescents.
Methods: Using a battery of self-report scales, three waves of data collection were conducted in a Chinese adolescent sample (N = 1,301). The co-developmental trajectories of Internet addiction and depressive symptoms were extracted by adopting parallel-process latent class growth modeling (PPLCGM). Multinomial logistic regression was performed to assess predictive factors.
Results: Four unique joint trajectory classes were detected: the Health Group (n = 912, 70.1%), Comorbidity-Worsening Group (n = 85, 6.5%), Asymptomatic-Comorbid Risk Group (n = 148, 11.4%), and Prominent Depressive Symptoms-Remission Group (n = 156, 12.0%). Individual, family, and school factors (e.g., gender, positive youth development, family function, academic performance) significantly predicted the membership in these distinct co-developmental trajectories.
Conclusion: Our findings illustrate that the joint development of Internet addiction and depressive symptoms among adolescents presents a heterogeneous distribution, which could better inform prevention and intervention strategies since each co-developmental trajectory may represent unique experience for adolescents who need targeted treatment. Various individual, family, and school factors are important predictors that play different roles in distinguishing the joint trajectories of Internet addiction and depressive symptoms during this critical developmental transition period.
Introduction
Internet addiction is defined as “excessive or uncontrolled urges in terms of Internet use” (1). Currently, adolescent Internet addiction has become a prime concern across countries and regions. The prevalence of Internet addiction among adolescents has been shown to vary greatly from 11.8% (European countries) to 20.6% (Canada) (2). In China, Internet addiction rates have been reported to reach 15.3% among adolescents (3). Internet addiction is associated with a range of detrimental physical and mental health issues, including sleep disturbances (4), emotional distress (5, 6), and poor interpersonal relationships (7). Characterized by “feelings of sadness and worthlessness, with diminished interest in things which were once enjoyed, and even having suicide ideation” (8), depressive symptoms are one of the most common correlates of Internet addiction (9, 10), making it necessary to survey this particularly relevant construct in conjunction with being addictive into the Internet. Epidemiological research has also frequently revealed that there is a high incidence of comorbidity between these disturbances (11, 12), and this comorbidity often results in a more chronic course and more severe psychiatric symptoms, a higher recurrence rate, and heavier burdens than single diseases (13, 14).
Theoretically, the relationship between Internet addiction and depressive symptoms should be reciprocal: based on the compensatory Internet use theory (15), adolescents who become depressed are more likely to engage in the Internet world, come in contact with virtual friends to alleviate negative emotions and compensate for psychological needs; meanwhile, according to the social displacement hypothesis, overindulgence into the Internet may usurp face-to-face communication and result in social isolation, thus heightening the chances of suffering from depression (16). Moreover, recent empirical studies that explored the temporal directional relationship between Internet addiction and depressive symptoms also supported the idea that Internet addiction and depressive symptoms reciprocally influence each other (17, 18). Although Internet addiction and depressive symptoms are theoretically and empirically entwined, the developmental overlap between Internet addiction developmental trajectories and depression developmental trajectories still remains unclear. Consequently, this study anticipated to probe their joint developmental courses among Chinese adolescents during their junior high school years. In addition, consecrating that the explanation for the high prevalence of comorbidities between Internet addiction and depressive symptoms among adolescents might be the basis of the etiopathogenesis and influencing factors shared between them, we also examined whether a series of individual, school and family factors were differentially associated with the longitudinal joint trajectory classes.
Distinct trajectories of Internet addiction and depressive symptoms among adolescents
A handful of studies have observed the evolution of Internet addiction. Specifically, using growth curve analyses, several researchers have shown that Internet addiction tends to increase as children enter puberty, but is initially moderate and subsequently decreases when adolescents reach the age range from 16 to 19 (19). However, these studies using latent curve modeling mainly displayed general developmental trends but ignored the heterogeneously distributed trajectories of adolescent Internet addiction, which might yield results of limited interpretability. This issue could be solved by adopting growth mixture models or latent class growth models for longitudinal data (20), which allows us to examine whether populations could be qualitatively differentiated into latent subgroups with distinct developmental trajectories.
Limited studies have examined the heterogeneous growth trajectories of Internet addiction over time (21–24). These studies identified four to six trajectory subgroups of Internet addiction. For example, Zhou et al. (24) identified four developmental trajectory subgroups of Internet addiction among youth experiencing the Wenchuan earthquake: a slowly rising group, a steadily rising group, a sharply falling group, and a sharply rising group. In another study, a sample of 3,079 Singaporean youth aged 7 to 19 years was longitudinally surveyed four times at one-year intervals, revealing six latent trajectory types across this period based on changes in Internet addiction related to pathological status (21).
Many studies have examined heterogeneous longitudinal patterns of depressive symptoms from childhood to adolescence (25–30). Typically, scholars have identified three to four distinct developmental trajectories of depressive symptoms over time. Ellis et al. (26) had reviewed 18 studies that examined the developmental heterogeneity of adolescent depression and found that previous studies reported a low-level stable trajectory of adolescent depression, and most of them also found both an increasing and a decreasing trajectory. Recent studies have confirmed these conclusions. For example, Ho et al. (31) also identified three trajectories—a “high but decreasing trajectory,” a “moderate and stable trajectory,” and a “low but increasing trajectory”—in adolescents through a three-year follow-up study.
These studies mentioned above highlight the importance of the longitudinal development of Internet addiction and depressive symptoms in adolescents. Nevertheless, there are still limitations that have not yet been addressed: most studies exclusively concern the heterogeneous development trajectories of either Internet addiction or depressive symptoms but do not pay close attention to the longitudinal overlap between them. In fact, researchers have reached the consensus that Internet addiction is often comorbid with depressive symptoms (10). Thus, the trajectories of adolescent Internet addiction might influence, and be influenced by depressive symptoms. Thus, it is expected that the two mental health issues will exhibit a similar developmental course. Examining the joint growth trajectories of Internet addiction and depressive symptoms is important for obtaining a better understanding of how these developmental courses evolve from early adolescence to middle adolescence. These issues are also crucial for establishing effective prevention or intervention strategies that consider the developmental relationships between Internet addiction and depressive symptoms. Consequently, the first aim of the present study was to investigate the joint development of Internet addiction and depressive symptoms among Chinese adolescents.
Predictive factors associated with Internet addiction and depressive symptoms
Substantial studies have reported on the predictive factors associated with Internet addiction and depressive symptoms (22, 31–33). In this study, based on the results of our previous studies on the prevalence and predictors of Internet addiction and depressive symptoms (3, 34), we selected a set of robust predictors for the current study, and those influential factors were classified as individual, family, and school variables.
Regarding individual factors, gender and positive youth development were chosen. The findings on gender differences have been mixed. Some studies have revealed that boys are usually more likely to get indulged into Internet than are their female peers (3, 35). However, because girls are more sensitive to the environment, they are at greater risk of experiencing depressive symptoms (36). There were also studies observed non-significant gender differences with respect to both Internet addiction and depressive symptoms (34, 37, 38). Different from gender, positive youth development has been discovered to be a robust predictor of both Internet addiction (39, 40) and depressive symptoms (41, 42). Researchers have consistently suggested that adolescents with low levels of positive youth development project the image of having fewer resources to effectively defend themselves, facilitating the development of problem behaviors and emotional disorders (43–47).
Concerning family factors, family structure, whether adolescents came from an only-child family or not, and family function were selected. To a greater extent, family non-intactness, encompassing divorce, separation, or remarriage, has also been a contributor to adolescent Internet addiction (48) and depressive symptoms (34). For instance, Ni et al. (49) suggested that having a single-parent family was significantly associated with Internet addiction. This is also suitable for adolescents’ depressive symptoms (50). Due to the implementation of the one-child policy in China during the preceding three decades, a significant number of families have been limited to having only one child. Extensive research has been conducted to examine potential disparities in psychological and behavioral development between children raised in single-child households and those from families with multiple children (51–53). Research has demonstrated that there are significant differences in Internet addiction (54) and depressive symptoms (34) between only children and non-only children in the Chinese adolescent population. Furthermore, given the importance of family as a source of emotional support and emotional warmth for adolescents, it should be no surprise that healthy family function has been verified to be a prominent protective factor against adolescents’ Internet addiction (55) and depressive symptoms (56). Adolescents who report family dysfunction issues, such as lack of communication, frequent conflict and indifferent atmospheres, have been found to be at high risk of being addictive toward the Internet (57) and becoming depressed (58). Thus, the adolescents’ perceptions of family function were also assessed.
As for school factors, academic performance was chosen. According to the academic incompetence hypothesis (59), inadequate academic performance or failure in academics could potentially diminish intrinsic resources among adolescents, thereby reducing their capacity to effectively manage addiction and depression. Empirical research likewise suggests that poor academic performance or academic failure may lead to the development of Internet addiction (60) and depressive symptoms (61). Specifically, the occurrence of substandard academic performance has the potential to trigger a range of adverse cognitive processes, such as diminished self-esteem (62), and negative interpersonal encounters, such as peer rejection (63), which have also been linked to an increased likelihood of Internet addiction and depressive symptoms.
These aforementioned findings suggest that both the Internet addiction and depressive symptoms of adolescents are influenced by various factors present within the ecosystem in which adolescents live. Nevertheless, it remains unclear whether these predictors might play the same role in the joint trajectory of Internet addiction and depressive symptoms. Failure to take the developmental trajectory and heterogeneity into account may generate limited generalizability and interpretability since different etiologic factors might operate to produce different levels of severity or different developmental trajectories of problems. Therefore, in the present study, we also examined a range of variables that were selected to include different domains termed individual variables (gender, positive youth development), family variables (single-child family, family function), and school variables (academic achievement). We aimed to provide an overall picture of what factors could predict membership in the conjoint trajectory groups of Internet addiction and depressive symptoms, which was the second aim of our study.
The present study
Overall, the present study aimed to explore (1) the joint developmental trajectories of Internet addiction and depressive symptoms among Chinese adolescents and (2) the individual, family, and school factors related to membership in these joint trajectories of Internet addiction and depressive symptoms among adolescents. Since no study to date has examined the joint trajectory classes of Internet addiction and depressive symptoms and the predictors of these classes, in this study, both of the goals were exploratory in nature, and no specific hypotheses were put forward. The present study is expected to help practitioners offer tailored prevention or intervention strategies for adolescents following distinct joint developmental trajectories of Internet addiction and depressive symptoms during their junior middle school years.
Methods
Participants and procedure
Quantitative surveys were administered to participants in October and November 2016 (T1; 1st semester of Grade 7), October and November 2017 (T2; 1st semester of Grade 8), and October 2018 (T3; 1st semester of Grade 9) in Shenzhen, Guangdong Province, China. Five districts of Shenzhen, which encompasses nine administrative regions, were randomly selected for the study. Within each selected district, one school was designated as the research focal point, leading to the inclusion of five secondary schools in total. Participants from the five schools were selected based on three criteria: (1) enrollment in the seventh grade, (2) obtaining permission from their legal guardians to participate, and (3) voluntary consent to be involved. In this study, we chose to assess participants collectively in the classroom, ensuring that all students completed the assessment under consistent conditions. Adolescents were guided to complete pen-and-paper questionnaires individually. A total of 1,544 adolescents with a mean age of 12.46 years old (SD = 0.63) participated in the first data collection. A total of 1,511 adolescents participated in the second data collection. A total of 1,480 adolescents participated in the third data collection. After cleaning the invalid data, 1,301 adolescents completed all three assessments. Among them, 666 (51.2%) were boys, 621 (47.7%) were girls, and 14 (1.1%) did not report their gender. See Table 1 for further demographic details regarding the participants. The study was conducted with the approval of both the Human Research Ethics Committee of the corresponding author and the administrative committees of the investigated schools. The dataset used in this study has been utilized in prior research, and has been published in several papers (54, 56, 64). The current study offers a novel analysis by focusing on the joint trajectories of Internet addiction and depressive symptoms, a perspective that differs both methodologically and theoretically from our earlier work.
Instruments
Internet addiction
We used the Chinese version of Young’s Internet Addiction Test (65) to assess adolescent Internet addiction. The scale includes 10 items in which adolescents react to these items according to whether they had expressed the listed behaviors in the past year (0 = “no,” 1 = “yes”). The total IA scores ranged from 0 to 10. The overall severity was evaluated by calculating the total score of 10 items. In the present study, the scale demonstrated good reliability, with Cronbach’s alphas of 0.76, 0.75, and 0.83 for T1, T2, and T3, respectively. According to previous research, 4 was considered the cutoff score for screening whether an adolescent was identified as having “Internet addiction” (3).
Depressive symptoms
The Chinese version of the Center for Epidemiological Studies Depression Scale [CES-D; (66)] was used to measure adolescent depressive symptoms. Prior studies have shown that the CES-D has good psychometric properties for Chinese adolescents (67). When assessed with this scale, adolescents were instructed to indicate how frequently they experienced depressive symptoms in the past week. All items were measured on a 4-point scale (0 = “rarely or none of the time,” 1 = “sometimes,” 2 = “often,” and 3 = “most or all of the time”). The total CES-D scores ranged from 0 to 60, with higher scores indicating more severe depressive symptoms. In our study, the CES-D exhibited good internal consistency, with the Cronbach’s alphas of 0. 85, 0.85, and 0.88 for T1, T2, and T3, respectively. Based on the suggestion of Kroenke and Spitzer (68), we have adopted a cutoff value of 16 for screening individuals with depressive symptoms.
Individual factors
Individual variables included gender and psychological competencies. Adolescents reported their gender (“boy” coded as “1,” “girl” coded as “0”). Psychological competencies were measured by the Chinese version of the Positive Youth Development Scale (CPYDS), which consists of 15 positive youth development constructs (69). Adolescents rated the CPYDS items on a 6-point Likert scale ranging from 1 “strongly disagree” to 6 “strongly agree.” A higher total score reflects greater psychological competence. The CPYDS has demonstrated excellent reliability among Chinese adolescent samples (70, 71). The Cronbach’s alpha in this study was 0.95.
Family factors
The family variables included family structure, single-child family or not, and family function. Adolescents reported whether they came from a single-child family or not (“only-child family” coded as “1,” “non-only child family” coded as “0”) and intact family or not (“intact family” coded as “1,” “non-intact family” coded as “0”). Family function was assessed with the nine-item Chinese version of the Family Assessment Instrument [CFAI; (72)]. Items were evaluated on a 5-point scale (1 = “very dissimilar” to 5 = “very similar”). The Cronbach’s alpha for family function in the present study was 0.86. The scores for nine items were averaged, with higher scores representing healthier family function.
School factors
The school variable included academic performance. Academic performance was assessed with a single item. Adolescents provided their answers to the question about their relative academic performance within their own class on a 5-point scale (1 = “poor” to 5 = “excellent”) (3). In this study, higher scores indicate greater academic performance.
Statistical analysis
We calculated the mean, standard deviations and correlations between Internet addiction and depressive symptoms across time points. Then, using the Mplus 8.0 software (73), we applied linear unconditional parallel-process latent class growth modeling (PPLCGM) to distinguish the joint longitudinal trajectories of Internet addiction and depressive symptoms from early adolescence (Grade 7) to middle adolescence (Grade 9). PPLCGM is an extension of the traditional latent class growth analysis (LCGA) that allows for the simultaneous consideration of multiple growth trajectories (74). This approach is particularly suitable for our research questions because it enables us to model the joint developmental processes of Internet addiction and depressive symptoms, as well as to identify distinct subgroups of individuals following similar trajectories over time. In reference to previous similar studies (74–76), the resulting classes of joint trajectories were compared and selected according to a series of fitting indices: (1) the Akaike Information Criterion (AIC), the smallest value represents the most parsimonious model; (2) the Bayesian Information Criterion (BIC), the smallest value presents the most parsimonious model; (3) the adjusted Bayesian Information Criterion (aBIC), the smallest value indicates the most parsimonious model; (4) the Lo–Mendell–Rubin Likelihood Ratio test (LMR-LRT), the model with significant p-values of LMR-LRT represents a better fit than the model with one less class; (5) the adjusted LMR-LRT (ALMR-LRT), the model with significant p-values of ALMR-LRT reflects a better fit than the model with one less class; (6) the Bootstrapped Likelihood Ratio test (BLRT), the model with significant p-values of BLRT represents a better fit than the model with one less class; and (7) the entropy, values ranging from 0 to 1, closer to 1 implies more accurate classification. The selection of the best-fitting solutions was based on theoretical coherence, including the substantive interpretability of the trajectory classes and the identification of trajectories without overfitting, as well as explanatory relevance (75). Additionally, we considered whether each class size comprised at least 5% of the sample (76). After that, we conducted a multinomial logistic regression to assess the role of various individual, family, and school variables in predicting joint trajectory class memberships.
Results
Descriptive statistics and correlations of variables
As Table 2 shows, the means and standard deviations for Internet addiction at each measurement wave were 1.55 (1.99), 1.62 (1.99), and 1.47 (2.13) for Time 1 to Time 3, respectively. The means and standard deviations for depressive symptoms at Time 1 to Time 3 were 13.66 (9.15), 13.76 (9.33), and 12.40 (9.31), respectively. The correlations across the three time points ranged from 0.21 to 0.39 for Internet addiction, and from 0.25 to 0.42 for depressive symptoms. At the same measurement wave, the correlations between Internet addiction and depressive symptoms were 0.33 for T1, 0.36 for T2, and 0.44 for T3, respectively. Additionally, the correlations between gender and T1 Internet addiction and T3 depressive symptoms were significant, and single-child family and family structure were both significantly associated with depressive symptoms at T2 and T3. Moreover, the correlations of predictors (positive youth development, family function, and academic performance) at T1 with Internet addiction at T1, T2, and T3 were statistically significant. Likewise, these predictors at T1 were also significantly associated with depressive symptoms at T1, T2, and T3. More details are presented in Table 2.
Table 2. Descriptive statistics and correlation analyses among Internet addiction, depressive symptoms, and predictive variables.
Joint trajectories of Internet addiction and depressive symptoms
We computed 1- to 6-class solutions for joint trajectory groups of Internet addiction and depressive symptoms. The model fit indices for these solutions are summarized in Table 3. The results showed that the values of AIC, BIC, and aBIC decreased from 1- to 6-class solutions, and these classes of solutions all had acceptable entropy (>0.80). We found significant BLRT in 2- to 6-classes, while the LMR-LRT and ALMR-LRT results suggested that the two-, three- and four-class solutions were suitable. Further observation confirmed that the 5-class to 6-class solution should be discarded because they included a subgroup comprising less than 5% of the total participants. Given that the model fit of the optimal trajectory class is indicated by smaller values of AIC, BIC, and aBIC, and a significant result of LMR-LRT, ALMR-LRT, and BLRT, as well as a higher entropy, after balancing the criteria of model fit indices, we considered the 4-class model of joint trajectory groups as the fittest solution for our data. As mentioned above, we chose 4 as the cutoff value for screening for Internet addiction, and 16 for depressive symptoms. After integrating multiple indicators of intercepts, slopes, and cutoff scores for Internet addiction and depressive symptoms, we labeled the four joint trajectory classes as the Health Group, Comorbidity-Worsening Group, Asymptomatic-Comorbid Risk Group, and Prominent Depressive Symptoms-Remission Group.
Table 3. Model fit indices for 1- to 6- class solutions for Internet addiction and depressive symptoms.
The first trajectory class (Health Group) included 70.1% of the adolescents (n = 912) with no or very few Internet addiction symptoms as well as depression episodes in the first assessment (intercepts =1.12 and 11.29, respectively; p < 0.001). Moreover, both Internet addiction and depressive symptoms slightly decreased throughout the three assessments (slopes = −0.26 and − 0.85, respectively; p < 0.001), with both scores being consistently below the cutoff value during the study period. The second trajectory class (Comorbidity-Worsening Group) comprised 6.5% of the adolescents (n = 85) with high levels of Internet addiction and depressive symptoms at baseline, and both increased rapidly and significantly during the three-year period. The Internet addiction score in this class was initially nearly the cutoff (intercept = 3.63, p < 0.001), and increased at a mean linear rate of 1.67 points at each measurement time (slope = 1.67, p < 0.001). The depressive symptoms in this class were highly similar to Internet addiction, with scores above the cutoff value at baseline (intercept = 20.63, p < 0.001) and a significantly positive mean slope value (slope = 2.94, p = 0.006). The third trajectory class (Asymptomatic-Comorbid Risk Group) included 11.4% of the adolescents (n = 148) with low initial scores (below the cutoff value) for both Internet addiction and depressive symptoms (intercepts = 1.69 and 12.06, respectively; p < 0.001). However, in this latent class, the Internet addiction and depressive symptom scores continually increased at the two subsequent assessment points (slopes = 1.14 and 1.65, respectively; p < 0.001), and depressive symptom scores ultimately increased nearly to the diagnostic criteria at the last assessment point. The fourth trajectory class (Prominent Depressive Symptoms-Remission Group) consisted of 12.0% of the adolescents (n = 156) with high Internet addiction scores (intercepts = 2.90, p < 0.001) and the highest depressive symptom scores (intercepts = 25.20, p < 0.001) at Time 1, both of which decreased during the three junior years. Depressive symptom scores in this class displayed a very rapid decline (slope = −3.13, p < 0.001), but scores were persistently higher than the cutoff score of 16 at each assessment point. Meanwhile, Internet addiction scores in this group decreased quite slowly (slope = −0.85, p < 0.001), and the scores were consistently lower than the cutoff score of 4 across the three assessments. Figure 1 shows the estimated growth parameters and plots for each of the four classes, respectively.
Figure 1. Estimated means of Internet addiction and depressive Symptoms in PLCGM. Y-axis indicates the means of Internet addiction/depressive symptoms; X-axis indicates the measurement times. T1–T3 represents Time 1–Time 3, respectively.
Predictor of the joint trajectory groups of Internet addiction and depressive symptoms
In consideration of the clinical intervention, in the current study, three groups with symptoms (Comorbidity-Worsening Group, Asymptomatic-Comorbid Risk Group, and Prominent Depressive Symptoms-Remission Group) should be the focus in comparing with the Health Group. Thereby, to offer effective and targeted interventions for these groups, we probed the role of individual factors (gender, positive youth development), family factors (family structure, whether come from only-child family, family function) and school factors (academic performance) in predicting the membership in the Comorbidity-Worsening Group, Asymptomatic-Comorbid Risk Group, and Prominent Depressive Symptoms-Remission Group, by comparing each of them with the Health Group. The results of the multinomial logistic regression analysis of these individual, family and school predictors are displayed in Table 4.
Table 4. Predictive effect of membership in the joint trajectory groups with the health group as the reference category.
Using the Health Group as the reference category, our results showed that family structure and whether come from only-child family had nonsignificant associations with distinct co-developmental trajectories of adolescent Internet addiction and depressive symptoms. However, gender, positive youth development, family function, and academic performance were significantly related to the three joint trajectories groups. To be specifically, compared to those in the Health Group, the participants in the Comorbidity-Worsening Group and Asymptomatic-Comorbid Risk Group were less likely to be boys (OR = 0.59 and 0.63, respectively). Moreover, compared with those in the Health Group, having more positive youth development and healthier family function both significantly decreased the odds of following the Comorbidity-Worsening Group (OR = 0.39 and 0.42, respectively), Asymptomatic-Comorbid Risk Group (OR = 0.57 and 0.75, respectively), and Prominent Depressive Symptoms-Remission Group (OR = 0.32 and 0.42, respectively). Additionally, reporting better academic performance significantly decreased the odds of following the Comorbidity-Worsening Group (OR = 0.64) only.
Discussion
Adopting a three-year longitudinal design combined with parallel-process latent class growth modeling, the present study addressed the co-developmental patterns of Internet addiction and depressive symptoms from early adolescence to middle adolescence, as well as the potential predictors related to individual, family and school variables. The findings revealed four distinct co-developmental patterns: Health Group, Comorbidity-Worsening Group, Asymptomatic-Comorbid Risk Group, and Prominent Depressive Symptoms-Remission Group. Furthermore, the predicted effects of gender, positive youth development, family function, and academic performance on the membership in the established joint trajectory subgroups were also endorsed by this study.
Joint developmental trajectories of Internet addiction and depressive symptoms among adolescents
As our findings revealed, Internet addiction and depressive symptoms jointly changed in a heterogeneous way from early adolescence to middle adolescence. Our findings indicated four different co-developmental trajectories of the two types of mental health concerns: Health Group, Comorbidity-Worsening Group, Asymptomatic-Comorbid Risk Group, and Prominent Depressive Symptoms-Remission Group. Within each subgroup, adolescents generally exhibited similar developmental patterns across two mental health issues, which supporting the idea that Internet addiction and depressive symptoms are inextricably linked (9, 77). However, the initial level of Internet addiction and depressive symptoms (i.e., low-low/high-high), growth patterns of Internet addiction and depressive symptoms (i.e., increasing/decreasing), and predominant symptoms (i.e., comorbidity, asymptomatic, and depressive symptoms only) varied across adolescents in different subgroups, providing additional support for heterogeneous joint trajectories of Internet addiction and depressive symptoms.
The present study successfully identified three congruent subgroups that exhibited comparable initial levels and consistent developmental patterns in terms of both Internet addiction and depressive symptoms (i.e., Health Group, Comorbidity-Worsening Group and Asymptomatic-Comorbid Risk Group). First, consistent with prior studies showing that most adolescents exhibit low or no Internet addictive behaviors (78) and depressive symptoms (79), we found that the majority of adolescents (70.1%) exhibited low levels of Internet addiction and depressive symptoms and remained healthy (the Health Group) throughout their three-year tenure in junior middle school. Our findings were also in line with previous developmental studies of Internet addiction (21, 22) and depressive symptoms (26).
Second, our research identified a Comorbidity-Worsening Group, comprising 6.5% of the sample population. Within this group, both Internet addiction and depressive symptoms started at relatively high levels and then increased over time. The developmental pattern of this subgroup is in accordance with the findings of studies showing that Internet addiction and depressive symptoms could exhibit a vicious cycle. The reason may be that the presence of Internet addiction among adolescents may contribute to the manifestation of depressive symptoms, subsequently reinforcing their inclination toward increased Internet engagement (18, 80, 81). Such reciprocal interaction perpetuates a self-reinforcing cycle, thereby engendering deleterious progression. Therefore, adolescents with co-morbid Internet addiction and depressive symptoms appear to be at a vulnerable stage and are experiencing a deterioration in development due to the mutually malignant effects of Internet addiction and depressive symptoms. This, to some extent, supports both the compensatory Internet use theory (15) and the social displacement hypothesis (16), which is also consistent with recent research implying the existence of shared neurobiological mechanisms, such as oxytocinergic and dopaminergic expression, between Internet addiction and depressive symptoms (82, 83). Notably, this finding emphasizes that the initial year of junior high school is a particularly critical period for detecting Internet addiction and depressive symptoms, as well as a pivotal opportunity for preventing the deterioration of Internet addiction and depressive symptoms. Additionally, these findings may provide valuable insights to scholars and clinicians that the earlier the intervention for Internet addiction and depressive symptoms is, the more effective it might be at mitigating them among adolescents.
Third, our study identified an Asymptomatic-Comorbid Risk Group (11.4%), in which Internet addiction and depressive symptoms were initially low but both increased rapidly across time. For this subgroup of adolescents, an increasing level of depressive symptoms reflects the inadequacy of emotion regulation strategies (84, 85); addictive behaviors into the Internet could serve as a means to help adolescents escape unpleasant emotions. It seems that the transition from childhood to adolescence represents a vulnerable period for the onset and escalation of both depressive symptoms and Internet addiction, as individuals may progress from being initially asymptomatic to having a co-occurring risk. The challenging process necessitates behavioral adjustments to cope with various biological, psychological, and social changes (86, 87). These adjustments may entail exposure to stressors and potentially traumatic experiences, which may trigger depressive symptoms and Internet addiction. Overall, the identification of the three congruent groups (i.e., Health Group, Comorbidity-Worsening Group and Asymptomatic-Comorbid Risk Group) suggested that Internet addiction and depressive symptoms exhibited similarities in developmental status and temporal trends among the majority of middle school students. Consequently, integrated interventions targeting both Internet addiction and depressive symptoms are recommended.
Regarding the Prominent Depressive Symptoms-Remission Group (12.0%), our results showed that depressive symptoms in this subgroup were at the highest level and then showed a rapid decreasing trend with time, whereas Internet addiction was at a relatively moderate level and exhibited a gradual decline over time, but did not reach the threshold of addiction disorder during the 3 years. Nonetheless, in this study, we did not find a subgroup characterized by elevated levels of Internet addiction alongside low levels of low depressive symptoms. Our findings support the idea that Internet addiction commonly occurs concomitantly with depressive symptoms, while depressive symptoms tend to manifest independently. This finding aligns with the outcomes reported in several prior research, which found that Internet addiction may result in depressive symptoms, rather than vice versa (88, 89). By intensive tracking over short periods of time, future researchers should further examine whether higher levels of Internet addiction indeed co-occur with depressive symptoms, or whether higher levels of Internet addiction may occur without depressive symptoms.
Predictor of the joint trajectories of Internet addiction and depressive symptoms
In the present study, after controlling for the effects of multiple factors, we found that positive youth development and family function significantly reduced the risk of membership in the Comorbidity-Worsening Group, Asymptomatic-Comorbid Risk Group and Prominent Depressive Symptoms-Remission Group compared to the Healthy Group. Our findings were in accordance with previous related studies on the relationship between positive youth development, family function and two forms of mental health problems (i.e., Internet addiction and depressive symptoms) (22, 90). This can be explained by development assets theory (91), which assumes that the developmental resources (both external and internal) that adolescents possess will facilitate effective coping with environmental stressors, thus minimizing the occurrence of various mental health problems (71, 91, 92). Related studies have further confirmed that adolescents are more likely to develop well and have fewer addiction and depression problems when they have access to a variety of resources. Thus, those who exhibit high levels of positive youth development are less likely to be plagued by Internet addiction and depressive symptoms.
In the present study, positive youth development was identified as an internal asset, that is an important predictor of adolescent mental health and a crucial protective factor against adolescent problem behaviors (47, 93). During adolescence, high levels of positive youth development are effective at fostering adolescents’ internal self-regulation (94) and could encourage individuals to effectively address encountered challenges, thereby substantially diminishing the probability of exacerbating Internet addiction (35, 39, 95) and depressive symptoms (96, 97). Family function, as an important external resource for adolescent development, has a significant impact on preventing the onset and continuity of adolescents’ mental health problems (98). This finding aligns with a substantial body of prior research investigating the impact of family on adolescents. These studies have documented that healthy family functioning, characterized by strong family cohesion, a warm family environment, and constructive parent–child interactions, is conducive to the healthy development of adolescents and substantially diminishes the likelihood of adolescent Internet addiction (99–102) and depressive symptoms (56, 103). Notably, in this study, positive youth development and family functioning were significantly associated with all three groups (the Comorbidity-Worsening Group, Asymptomatic-Comorbid Risk Group, and Prominent Depressive Symptoms-Remission Group) compared with the Healthy Group, confirming the predictive effect of positive youth development and family function on both the initial level and developmental trends of Internet addiction and depressive symptoms. To some extent, our study extends previous studies by indicating that positive youth development and family function not only have transient but also long-term effects on adolescents’ Internet addiction and depressive symptoms.
In addition, we found that low academic performance in early adolescence increased the likelihood of belonging to the Comorbidity-Worsening Group compared to adolescents in the Health Group. This finding is consistent with the outcomes of a recent investigation conducted on middle school students in China, which revealed that high academic performance was indicative of low-risk depressive symptom trajectories (104). Furthermore, it partially supports the academic incompetence hypothesis (59), in which failure in academic performance erodes individuals’ intrinsic resources, decreasing their ability to cope with addiction and depression. Thus, challenged by academic failure, these co-morbid adolescents may experience more severe distress, which may trigger a worsening of Internet addiction and depressive symptoms. It is worth noting that the present study found that the effects of poor academic performance on the Asymptomatic-Comorbid Risk Group and the Prominent Depressive Symptoms-Remission Group were not significant. This finding implies that the effects of poor academic performance are significant solely when Internet addiction and depressive symptoms are both at high risk in the initial state of adolescence. For adolescents with relatively low levels of depressive symptoms and Internet addiction (the Asymptomatic-Comorbid Risk Group), and for adolescents with only high levels of depressive symptoms but no Internet addiction (the Prominent Depressive Symptoms-Remission Group), the impact of academic underachievement is not proximal enough to compromise functioning.
Another noteworthy finding was that girls were significantly more likely to belong to the Comorbidity-Worsening Group and the Asymptomatic-Comorbid Risk Group than were boys. This outcome aligns with prior research showing that the adverse consequences of Internet use on depression are more severe for females than for males (105), while the prevalence of Internet addiction is greater among males than females (106). One reasonable explanation is that this discrepancy may be attributed to divergent biological changes and developmental rates between boys and girls (107). Specifically, during puberty, surges in estrogen and other hormones in girls can potentially disrupt internal homeostasis. Consequently, girls may exhibit heightened sensitivity to psychosocial factors such as stress (107). This heightened vulnerability may contribute to overindulgence in the Internet and exacerbate internalized issues (e.g., depression), surpassing those experienced by boys (108, 109).
To summarize, the present study has identified positive youth development, family function, academic performance, and gender as significant predictors of the joint developmental trajectories of Internet addiction and depressive symptoms among adolescents. Our research has determined that certain variables exert a similar and universally applicable influence. Specifically, our findings underscore the robust influence of positive youth development and family functioning both as protective factors in distinguishing between the Comorbidity-Worsening Group, Asymptomatic-Comorbid Risk Group, Prominent Depressive Symptoms-Remission Group, and the Health Group, in accordance with the development assets theory. Positive youth development fosters internal self-regulation, and healthy family function provides external support, both of which contribute to the trajectory with both immediate and enduring implications for adolescent mental health. Additionally, our study identified particular variables, noting that poor academic achievement could only differentiate the Comorbidity-Worsening Group from the Health Group, while gender enables the differentiation of the Comorbidity-Worsening Group, Asymptomatic-Comorbid Risk Group, and the Health Group. Understanding these complex relationships could inform the development of more nuanced and effective preventive measures.
Limitations, strengths, and implications
Several limitations should be noted. First, although this study investigated Internet addiction and depressive symptoms from early to middle adolescence, it failed to track the progression of these symptoms throughout adolescence. Consequently, further studies are needed to validate and broaden these findings by encompassing a wider age range (i.e., primary, middle, to high school) to gain a comprehensive understanding of the long-term co-trajectories of Internet addiction and depressive symptoms. Second, our study exclusively examined the self-reported measures of Internet addiction and depressive symptoms. Therefore, it is important to acknowledge that participants’ responses might have been influenced by social desirability bias and self-presentation concerns, which could introduce common method bias. Future researchers are encouraged to gather data from multiple sources such as peers, teachers, and parents. Third, the current study has not fully accounted for stable individual characteristics that may influence the development of both Internet addiction and depressive symptoms. For instance, we did not consider the potential role of boredom proneness, which, as suggested by recent literature, could be a significant predictor of both depressive symptoms and Internet addiction (110, 111). Future research should integrate measures of boredom proneness and other stable individual differences to enhance the understanding of these complex dynamics. Fourth, the annual intervals between assessments may have allowed for the influence of significant life events, potentially introducing variability in the reported Internet addiction and depressive symptoms. These life events, such as changes in family structure, academic pressure, or social relationships, might have affected the mental health trajectories of our participants in ways that our study design does not fully capture. Further research with more frequent assessment points, including an evaluation of life events, is necessary to better understand these dynamics. Finally, our data were collected between 2016 and 2018. Given the rapid pace of technological change and the evolving nature of adolescent behaviors and mental health, some aspects of our findings might not fully reflect the current state of the variables under investigation. Nevertheless, we believe that the longitudinal design of our study and the robust co-development of Internet addiction and depressive symptoms might provide valuable insights. Future studies may benefit from incorporating more recent data to assess the ongoing development of these mental health concerns and to validate the generalizability of our findings in the current context.
Despite the aforementioned limitations, several important strengths emerged from the present study. First, this study utilized a longitudinal design of three waves covering the transition from early adolescence through middle adolescence, providing new insight into the joint developmental process of Internet addiction and depressive symptoms in this crucial developmental period. Second, by employing a person-centered, multi-trajectory approach, our study detected heterogeneous co-developmental trajectories of two prevalent psychological issues (Internet addiction and depressive symptoms) within a substantial cohort of Chinese adolescents, contributing to a profound and comprehensive understanding of the intricate nature of the concurrent developmental patterns of Internet addiction and depressive symptoms. Third, this study examined how individual, family, and school factors might relate to the co-developmental trajectories of Internet addiction and depressive symptoms. Such analyses advanced the existing knowledge on the risk and protective factors associated with these co-developmental patterns, and thereby enhanced our understanding of how adolescents’ Internet addiction and depressive symptoms could be effectively prevented.
The findings of our study hold significant implications for the evaluation, prevention, and intervention of Internet addiction and depressive symptoms among adolescents. The identification of four distinct subgroups implies that prevention and intervention approaches for adolescent Internet addiction and depressive symptoms should adopt different focal points and targeted strategies tailored to the specific co-developmental patterns of adolescents. On the one hand, the discovery of the Comorbidity-Worsening Group and Asymptomatic-Comorbid Risk Group revealed the persistent co-occurrence of Internet addiction and depressive symptoms in adolescents, suggesting that interventions for Internet addiction and depressive symptoms should be integrated. On the other hand, the detection of distinct co-development trajectories of Internet addiction and depressive symptoms implies that customized interventions targeting these two mental health issues may yield optimal outcomes for diverse individuals. For example, interventions that primarily address alleviating depressive symptoms would be most suitable for the Prominent Depressive Symptoms-Remission Group.
Furthermore, early intervention efforts should be tailored based on group membership, given that protective and risk factors and their combinations vary across concomitant trajectories of Internet addiction and depressive symptoms. For example, after taking into account the effects of individual, family, and school factors, positive youth development and family functioning emerged as significant protective factors linked to the Comorbidity-Worsening Group, Asymptomatic-Comorbid Risk Group and Prominent Depressive Symptoms-Remission Group. Thus, it is imperative for schools and families to collaborate effectively to cultivate junior high school students’ intrinsic positive resources, such as competence, connection, resilience, and confidence, to better address the issue of Internet addiction and depressive symptoms among adolescents. Meanwhile, preventive initiatives should focus on promoting family cohesion, cultivating a harmonious family atmosphere, and reducing family discord to make the family function well. In addition, poor academic performance was a significant risk factor associated with the Comorbidity-Worsening Group. This finding suggests that parents and teachers should keep close tabs on adolescents with co-morbid Internet addiction and depressive symptoms. Particularly when adolescents underperform academically, teaching emotion regulation strategies and monitoring online activities should be provided in a timely manner to reduce the co-worsening of Internet addiction and depressive symptoms in adolescents.
Data availability statement
The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.
Ethics statement
The studies involving humans were approved by the Human Research Ethics Committee of Shenzhen University. The studies were conducted in accordance with the local legislation and institutional requirements. Written informed consent for participation in this study was provided by the participants’ legal guardians/next of kin.
Author contributions
JZ: Conceptualization, Data curation, Formal analysis, Investigation, Writing – original draft. EW: Conceptualization, Data curation, Formal analysis, Investigation, Writing – original draft. LZ: Funding acquisition, Project administration, Writing – review & editing. XC: Funding acquisition, Project administration, Writing – review & editing.
Funding
The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was supported by Humanities and Social Sciences of Ministry of Education Planning Foundation (grant 23YTA190002), Guangdong Philosophy and Social Science Planning 2023Co-construction Proiect (Grant GD23XXL17), Youth Research Project of Shenzhen University 2035Outstanding Research Plan (Grant ZYON23 11), Revitalization Project of Humanities and Social Sciences, Shenzhen University (grant WKZX0311), and Yunnan Provincial Department of Education Research Project 2024: Study on Crisis Prevention and Response for Private University Students (grant 2024J1354).
Acknowledgments
The authors are grateful to all the participants who participated in the questionnaire.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Publisher’s note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
References
1. Young, KS . Internet addiction: the emergence of a new clinical disorder. Cyber Psychol Behav. (1998) 1:237–44. doi: 10.1089/cpb.1998.1.237
2. Blachnio, A, Przepiórka, A, Gorbaniuk, O, Benvenuti, M, Ciobanu, AM, Senol-Durak, E, et al. Cultural correlates of internet addiction. Cyberpsychol Behav Soc Netw. (2019) 22:258–63. doi: 10.1089/cyber.2018.0667
3. Chi, X, Hong, X, and Chen, X. Profiles and sociodemographic correlates of internet addiction in early adolescents in southern China. Addict Behav. (2020) 106:106385. doi: 10.1016/j.addbeh.2020.106385
4. Alimoradi, Z, Lin, CY, Brostrom, A, Bulow, PH, Bajalan, Z, Griffiths, MD, et al. Internet addiction and sleep problems: a systematic review and meta-analysis. Sleep Med Rev. (2019) 47:51–61. doi: 10.1016/j.smrv.2019.06.004
5. Diotaiuti, P, Mancone, S, Corrado, S, De Risio, A, Cavicchiolo, E, Girelli, L, et al. Internet addiction in young adults: the role of impulsivity and codependency. Front Psych. (2022) 13:893861. doi: 10.3389/fpsyt.2022.893861
6. Ismail, WSW, Sim, ST, Tan, KA, Bahar, N, Ibrahim, N, Mahadevan, R, et al. The relations of internet and smartphone addictions to depression, anxiety, stress, and suicidality among public university students in Klang Valley, Malaysia. Perspect Psychiatr Care. (2020) 56:949–55. doi: 10.1111/ppc.12517
7. Seo, M, Kang, HS, and Yom, YH. Internet addiction and interpersonal problems in Korean adolescents. Comput Inform Nurs. (2009) 27:226–33. doi: 10.1097/NCN.0b013e3181a91b3f
8. Thapar, A, Collishaw, S, Pine, DS, and Thapar, AK. Depression in adolescence. Lancet. (2012) 379:1056–67. doi: 10.1016/s0140-6736(11)60871-4
9. Cai, H, Bai, W, Sha, S, Zhang, L, Chow, IHI, Lei, S-M, et al. Identification of central symptoms in internet addictions and depression among adolescents in Macau: a network analysis. J Affect Disord. (2022) 302:415–23. doi: 10.1016/j.jad.2022.01.068
10. Carli, V, Durkee, T, Wasserman, D, Hadlaczky, G, Despalins, R, Kramarz, E, et al. The association between pathological internet use and comorbid psychopathology: a systematic review. Psychopathology. (2013) 46:1–13. doi: 10.1159/000337971
11. Geng, JY, Han, L, Gao, FQ, Jou, M, and Huang, CC. Internet addiction and procrastination among Chinese young adults: a moderated mediation model. Comput Hum Behav. (2018) 84:320–33. doi: 10.1016/j.chb.2018.03.013
12. Tang, CS-K, Koh, YW, and Gan, Y. Addiction to internet use, online gaming, and online social networking among young adults in China, Singapore, and the United States. Asia Pac J Public Health. (2017) 29:673–82. doi: 10.1177/1010539517739558
13. de Vries, HT, Nakamae, T, Fukui, K, Denys, D, and Narumoto, J. Problematic internet use and psychiatric co-morbidity in a population of Japanese adult psychiatric patients. BMC Psychiatry. (2018) 18:9. doi: 10.1186/s12888-018-1588-z
14. Wang, X, Liu, ZR, Li, YX, Li, GH, and Huang, YQ. Association of comorbidity of mood and anxiety disorders with suicidal behaviors. J Affect Disord. (2018) 227:810–6. doi: 10.1016/j.jad.2017.11.006
15. Kardefelt-Winther, D . A conceptual and methodological critique of internet addiction research: towards a model of compensatory internet use. Comput Hum Behav. (2014) 31:351–4. doi: 10.1016/j.chb.2013.10.059
16. Kraut, R, Patterson, M, Lundmark, V, Kiesler, S, and Scherlis, W. Internet paradox: a social technology that reduces social involvement and psychological well-being? Am Psychol. (1998) 53:1017–31. doi: 10.1037/0003-066X.53.9.1017
17. Tian, Y, Qin, N, Cao, S, and Gao, F. Reciprocal associations between shyness, self-esteem, loneliness, depression and internet addiction in Chinese adolescents. Addict Res Theory. (2020) 29:98–110. doi: 10.1080/16066359.2020.1755657
18. Yang, X, Guo, WJ, Tao, YJ, Meng, YJ, Wang, HY, Li, XJ, et al. A bidirectional association between internet addiction and depression: a large-sample longitudinal study among Chinese university students. J Affect Disord. (2022) 299:416–24. doi: 10.1016/j.jad.2021.12.013
19. Tóth-Király, I, Morin, AJS, Hietajärvi, L, and Salmela-Aro, K. Longitudinal trajectories, social and individual atecedents, and outcomes of problematic internet use among late adolescents. Child Dev. (2021) 92:E653–73. doi: 10.1111/cdev.13525
20. Muthén, B, and Muthén, LK. Integrating person-centered and variable-centered analyses: growth mixture modeling with latent trajectory classes. Alcohol Clin Exp Res. (2000) 24:882–91. doi: 10.1111/j.1530-0277.2000.tb02070.x
21. Choo, H, Chng, GS, Gentile, DA, and Lau, SPC. The role of peer support in the growth trajectory of pathological internet use among youth: a protective factor. Cyberpsychol Behav Soc Netw. (2021) 24:558–65. doi: 10.1089/cyber.2020.0054
22. Huang, P, Zhou, Y, Li, D, Jia, J, Xiao, J, Liu, Y, et al. Developmental trajectories of adolescent internet addiction: interpersonal predictors and adjustment outcomes. Res Child Adolesc Psychopathol. (2022) 51:355–67. doi: 10.1007/s10802-022-00987-1
23. Li, GM, Hou, GY, Yang, D, Jian, H, and Wang, WJ. Relationship between anxiety, depression, sex, obesity, and internet addiction in Chinese adolescents: a short-term longitudinal study. Addict Behav. (2019) 90:421–7. doi: 10.1016/j.addbeh.2018.12.009
24. Zhou, X, Zhen, R, and Wu, X. Trajectories of problematic internet use among adolescents over time since Wenchuan earthquake. Comput Hum Behav. (2018) 84:86–92. doi: 10.1016/j.chb.2018.02.030
25. Costello, DM, Swendsen, J, Rose, JS, and Dierker, LC. Risk and protective factors associated with trajectories of depressed mood from adolescence to early adulthood. J Consult Clin Psychol. (2008) 76:173–83. doi: 10.1037/0022-006x.76.2.173
26. Ellis, RER, Seal, ML, Simmons, JG, Whittle, S, Schwartz, OS, Byrne, ML, et al. Longitudinal trajectories of depression symptoms in adolescence: psychosocial risk factors and outcomes. Child Psychiatry Hum Dev. (2017) 48:554–71. doi: 10.1007/s10578-016-0682-z
27. Hou, J, and Chen, Z. The trajectories of adolescent depressive symptoms: identifying latent subgroups and risk factors. Acta Psychol Sin. (2016) 48:957–68. doi: 10.3724/SP.J.1041.2016.00957
28. Lin, C-J, Chang, L-Y, Wu, C-C, and Chang, H-Y. The effect of childhood depression trajectories on sugar-sweetened beverage habit trajectories in adolescence: exploring sleep problems as a mediator. Appetite. (2023) 194:107199. doi: 10.1016/j.appet.2023.107199
29. Martinez, MM, and Armenta, BE. Trajectories of depressive symptoms among north American indigenous adolescents: considering predictors and outcomes. Child Dev. (2020) 91:932–48. doi: 10.1111/cdev.13268
30. Wickrama, KAS, Wickrama, T, and Lott, R. Heterogeneity in youth depressive symptom trajectories: social stratification and implications for young adult physical health. J Adolesc Health. (2009) 45:335–43. doi: 10.1016/j.jadohealth.2009.04.018
31. Ho, YC, Chiou, HY, Molloy, L, Lin, KC, Chang, PC, and Chang, HJ. Identifying differential trajectories and predictors for depressive symptoms in adolescents using latent class growth analysis: a population-based cohort study. J Adolesc. (2023) 95:879–92. doi: 10.1002/jad.12161
32. Çelik, D, and Haney, M. The relationship between depression, healthy lifestyle behaviors and internet addiction: a cross-sectional study of the athlete university students in Turkey. Front Psych. (2023) 14:1222931. doi: 10.3389/fpsyt.2023.1222931
33. Lin, MP, Wu, JYW, You, JN, Hu, WH, and Yen, CF. Prevalence of internet addiction and its risk and protective factors in a representative sample of senior high school students in Taiwan. J Adolesc. (2018) 62:38–46. doi: 10.1016/j.adolescence.2017.11.004
34. Chi, X, Liu, X, Huang, Q, Huang, L, Zhang, P, and Chen, X. Depressive symptoms among junior high school students in southern China: prevalence, changes, and psychosocial correlates. J Affect Disord. (2020) 274:1191–200. doi: 10.1016/j.jad.2020.05.034
35. Chung, TWH, Sum, SMY, and Chan, MWL. Adolescent internet addiction in Hong Kong: prevalence, psychosocial correlates, and prevention. J Adolesc Health. (2019) 64:S34–43. doi: 10.1016/j.jadohealth.2018.12.016
36. Salk, RH, Hyde, JS, and Abramson, LY. Gender differences in depression in representative national samples: Meta-analyses of diagnoses and smptoms. Psychol Bull. (2017) 143:783–822. doi: 10.1037/bul0000102
37. Fan, Y . Influence of internet addiction disorder on undergraduates' physical activities:a moderating effect of perceived social support. J Tianjin Univ Sport. (2020) 35:423–427+459.
38. Zhou, M, Zhang, G, Rozelle, S, Kenny, K, and Xue, H. Depressive symptoms of Chinese children: prevalence and correlated factors among subgroups. Int J Environ Res Public Health. (2018) 15:283. doi: 10.3390/ijerph15020283
39. Shek, DT, and Yu, L. Adolescent internet addiction in Hong Kong: prevalence, change, and correlates. J Pediatr Adolesc Gynecol. (2016) 29:S22–30. doi: 10.1016/j.jpag.2015.10.005
40. Yu, L, and Shek, DTL. Internet addiction in Hong Kong adolescents: a three-year longitudinal study. J Pediatr Adolesc Gynecol. (2013) 26:S10–7. doi: 10.1016/j.jpag.2013.03.010
41. Travers, ASM, and Mahalik, JR. Positive youth development as a protective factor for adolescents at risk for depression and alcohol use. Appl Dev Sci. (2019) 25:322–31. doi: 10.1080/10888691.2019.1634569
42. Zhou, Z, Shek, DTL, Zhu, X, and Dou, D. Positive youth development and adolescent depression: a longitudinal study based on mainland Chinese high school students. Int J Environ Res Public Health. (2020) 17:4457. doi: 10.3390/ijerph17124457
43. Guerra, NG, and Bradshaw, CP. Linking the prevention of problem behaviors and positive youth development: Core competencies for positive youth development and risk prevention. New Dir Child Adolesc Dev. (2008) 2008:1–17. doi: 10.1002/cd.225
44. Schwartz, SJ, Phelps, E, Lerner, JV, Huang, S, Brown, CH, Lewin-Bizan, S, et al. Promotion as prevention: positive youth development as protective against tobacco, alcohol, lllicit drug, and sex initiation. Appl Dev Sci. (2010) 14:197–211. doi: 10.1080/10888691.2010.516186
45. Shek, DTL, and Leung, H. Positive youth development, life satisfaction, and problem behaviors of adolescents in intact and non-intact families in Hong Kong. Front Pediatr. (2013) 1:18. doi: 10.3389/fped.2013.00018
46. Sun, RC, and Shek, DT. Positive youth development, life satisfaction and problem behaviour among Chinese adolescents in Hong Kong: a replication. Soc Indic Res. (2012) 105:541–59. doi: 10.1007/s11205-011-9786-9
47. Urke, HB, Holsen, I, and Larsen, T. Positive youth development and mental well-being in late adolescence: the role of body appreciation. Findings from a prospective study in Norway. Front Psychol. (2021) 12:696198. doi: 10.3389/fpsyg.2021.696198
48. So, S-O, Chung-Song, K, and Myung, J-S. A study of predicting variables for internet addiction in adolescence. Korean J Health Psychol. (2011) 16:521–35. doi: 10.17315/kjhp.2011.16.3.006
49. Ni, X, Yan, H, Chen, S, and Liu, Z. Factors influencing internet addiction in a sample of freshmen university students in China. Cyberpsychol Behav. (2009) 12:327–30. doi: 10.1089/cpb.2008.0321
50. Guo, L, and Zhang, Z. Childhood experience, family/school factors and depressive emotion in middle and high school studens. Chin Ment Health J. (2003) 17:458–61.
51. Foster, JD, Raley, JR, and Isen, JD. Further evidence that only children are not more narcissistic than individuals with siblings. Personal Individ Differ. (2020) 161:109977. doi: 10.1016/j.paid.2020.109977
52. Li, YF, Liu, LJ, Lv, Y, Xu, LY, Wang, Y, and Huntsinger, CS. Mother-child and teacher-child relationships and their influences on Chinese only and non-only children's early social behaviors: the moderator role of urban-rural status. Child Youth Serv Rev. (2015) 51:108–16. doi: 10.1016/j.childyouth.2015.01.023
53. Yang, JY, Hou, X, Wei, DT, Wang, KC, Li, YD, and Qiu, J. Only-child and non-only-child exhibit differences in creativity and agreeableness: evidence from behavioral and anatomical structural studies. Brain Imaging Behav. (2017) 11:493–502. doi: 10.1007/s11682-016-9530-9
54. Wang, E, Zhang, J, Dong, Y, Xiao, J, Qu, D, Shan, H, et al. Vicious circle of family dysfunction and adolescent internet addiction: do only child and non-only child exhibit differences? Curr Psychol. (2023) 43:827–38. doi: 10.1007/s12144-023-04350-5
55. Kilic, M, Avci, D, and Uzuncakmak, T. Internet addiction in high school students in Turkey and multivariate analyses of the underlying factors. J Addict Nurs. (2016) 27:39–46. doi: 10.1097/jan.0000000000000110
56. Wang, E, Zhang, J, Peng, S, and Zeng, B. The association between family function and adolescents' depressive symptoms in China: a longitudinal cross-lagged analysis. Front Psych. (2021) 12:744976. doi: 10.3389/fpsyt.2021.744976
57. Kwon, S-K, and Jang, E-Y. Internet use among children: an exploratory study of comorbid disorders and predictors. Korean J Clin Psychol. (2010) 29:1067–86. doi: 10.15842/kjcp.2010.29.4.009
58. Zhou, JH, Li, X, Zou, Y, and Gong, X. Longitudinal relations among family dysfunction, depressive symptoms, and cyberbullying involvement in Chinese early adolescents: disentangling between- and within-person associations. Dev Psychopathol. (2022) 36:1–9. doi: 10.1017/s0954579422001274
59. Moilanen, KL, Shaw, DS, and Maxwell, KL. Developmental cascades: externalizing, internalizing, and academic competence from middle childhood to early adolescence. Dev Psychopathol. (2010) 22:635–53. doi: 10.1017/S0954579410000337
60. Koo, K, Nyunt, G, and Wang, BS. Who spends too much time online? Associated factors of internet addiction among international college students in the United States. J Int Stud. (2021) 11:122–43. doi: 10.32674/jis.v11i1.2063
61. Feng, TL, Jia, XY, Pappas, L, Zheng, XJ, Shao, T, Sun, LT, et al. Academic performance and the link with depressive symptoms among rural han and minority Chinese adolescents. Int J Environ Res Public Health. (2022) 19:6026. doi: 10.3390/ijerph19106026
62. Zheng, LR, Atherton, OE, Trzesniewski, K, and Robins, RW. Are self-esteem and academic achievement reciprocally related? Findings from a longitudinal study of Mexican-origin youth. J Pers. (2020) 88:1058–74. doi: 10.1111/jopy.12550
63. Veronneau, MH, Vitaro, F, Brendgen, M, Dishion, TJ, and Tremblay, RE. Transactional analysis of the reciprocal links between peer experiences and academic achievement from middle childhood to early adolescence. Dev Psychol. (2010) 46:773–90. doi: 10.1037/a0019816
64. Chen, S, Qu, D, Bu, H, Liang, K, Zhang, P, and Chi, X. Changes in the network association of internet addiction among heterogeneous high-risk adolescents. Acta Psychol Sin. (2023) 55:1465–76. doi: 10.3724/sp.J.1041.2023.01465
65. Shek, DT, Tang, VM, and Lo, CY. Internet addiction in Chinese adolescents in Hong Kong: assessment, profiles, and psychosocial correlates. Sci World J. (2008) 8:776–87. doi: 10.1100/tsw.2008.104
66. Zhang, J, Wu, Z, Fang, G, Li, J, Xin, H, and Chen, Z. Development of the Chinese age norms of CES-D in urban area. Chin Ment Health J. (2010) 24:139–43.
67. Huang, Y, Zhao, Q, and Li, C. How interpersonal factors impact the co-development of depression and non-suicidal self-injury in Chinese early adolescents. Acta Psychol Sin. (2021) 53:515–26. doi: 10.3724/sp.J.1041.2021.00515
68. Kroenke, K, and Spitzer, RL. The PHQ-9: a new depression diagnostic and severity measure. Psychiatr Ann. (2002) 32:509–15. doi: 10.3928/0048-5713-20020901-06
69. Shek, DTL, Sin, AMH, and Lee, TY. The Chinese positive youth development scale: a validation study. Res Soc Work Pract. (2007) 17:380–91. doi: 10.1177/1049731506296196
70. Shek, DT, and Ma, CM. Dimensionality of the Chinese positive youth development scale: confirmatory factor analyses. Soc Indic Res. (2010) 98:41–59. doi: 10.1007/s11205-009-9515-9
71. Wang, E, Zhang, J, Mu, W, Huang, L, and Chi, X. Dynamic interaction between positive youth development and externalizing behaviors among early adolescents: a three-year longitudinal study. Chin J Appl Psychol. (2022) 28:424–32.
72. Shek, DTL, Leung, H, and Lu, S. Perceived family life quality in junior secondary school students in Hong Kong. Soc Indic Res. (2014) 117:757–75. doi: 10.1007/s11205-013-0397-5
73. Muthén, L. K., and Muthén, B. O. (2010). Growth modelling with latent variable using Mplus: advanced growth models, survival analysis and missing data. In Mplus short courses. Available at: http://www.statmodel.com/download/Topic%204new.pdf.
74. Zhou, Y, Zheng, H, Liang, Y, Wang, J, Han, R, and Liu, Z. Joint developmental trajectories of bullying and victimization from childhood to adolescence: a parallel-process latent class growth analysis. J Interpers Violence. (2022) 37:NP1759–83. doi: 10.1177/0886260520933054
75. Lo Coco, G, Salerno, L, Albano, G, Pazzagli, C, Lagetto, G, Mancinelli, E, et al. Psychosocial predictors of trajectories of mental health distress during the COVID-19 pandemic: a four-wave panel study. Psychiatry Res. (2023) 326:115262. doi: 10.1016/j.psychres.2023.115262
76. Nylund, KL, Asparoutiov, T, and Muthen, BO. Deciding on the number of classes in latent class analysis and growth mixture modeling: a Monte Carlo simulation study. Struct Equ Model Multidiscip J. (2007) 14:535–69. doi: 10.1080/10705510701575396
77. Zhao, Y, Qu, DY, Chen, SY, and Chi, XL. Network analysis of internet addiction and depression among Chinese college students during the COVID-19 pandemic: a longitudinal study. Comput Hum Behav. (2023) 138:107424. doi: 10.1016/j.chb.2022.107424
78. Pan, YC, Chiu, YC, and Lin, YH. Systematic review and meta-analysis of epidemiology of internet addiction. Neurosci Biobehav Rev. (2020) 118:612–22. doi: 10.1016/j.neubiorev.2020.08.013
79. Shorey, S, Ng, ED, and Wong, CHJ. Global prevalence of depression and elevated depressive symptoms among adolescents: a systematic review and meta-analysis. Br J Clin Psychol. (2022) 61:287–305. doi: 10.1111/bjc.12333
80. Jun, S . The reciprocal longitudinal relationships between mobile phone addiction and depressive symptoms among Korean adolescents. Comput Hum Behav. (2016) 58:179–86. doi: 10.1016/j.chb.2015.12.061
81. Zhao, L, Li, X, Yang, Q, Peng, YH, Jiang, LH, Jia, P, et al. The longitudinal association between internet addiction and depressive and anxiety symptoms among Chinese adolescents before and during the COVID-19 pandemic. Front Public Health. (2023) 10:1096660. doi: 10.3389/fpubh.2022.1096660
82. Annunzi, E, Cannito, L, Bellia, F, Mercante, F, Vismara, M, Benatti, B, et al. Mild internet use is associated with epigenetic alterations of key neurotransmission genes in salivary DNA of young university students. Sci Rep. (2023) 13:22192. doi: 10.1038/s41598-023-49492-5
83. Tereshchenko, SY . Neurobiological risk factors for problematic social media use as a specific form of internet addiction: a narrative review. World J Psychiatry. (2023) 13:160–73. doi: 10.5498/wjp.v13.i5.160
84. Anniko, MK, Boersma, K, and Tillfors, M. Investigating the mediating role of cognitive emotion regulation in the development of adolescent emotional problems. Nord Psychol. (2018) 70:3–16. doi: 10.1080/19012276.2017.1323665
85. Arnarson, E, Matos, AP, Salvador, C, Ribeiro, C, de Sousa, B, and Craighead, WE. Longitudinal study of life events, well-being, emotional regulation and depressive symptomatology. J Psychopathol Behav Assess. (2016) 38:159–71. doi: 10.1007/s10862-015-9524-8
86. Li, J, Bai, R, Wang, Y, and Liu, X. The relationship between developmental trajectories of adolescents’depression and self-injury: a two-year longitudinal study. Psychol Dev Educ. (2023) 39:429–38. doi: 10.16187/j.cnki.issn1001-4918.2023.03.14
87. Nelson, EE, Leibenluft, E, McClure, EB, and Pine, DS. The social re-orientation of adolescence: a neuroscience perspective on the process and its relation to psychopathology. Psychol Med. (2005) 35:163–74. doi: 10.1017/s0033291704003915
88. Kojima, R, Shinohara, R, Akiyama, Y, Yokomichi, H, and Yamagata, Z. Temporal directional relationship between problematic internet use and depressive symptoms among Japanese adolescents: a random intercept, cross-lagged panel model. Addict Behav. (2021) 120:106989. doi: 10.1016/j.addbeh.2021.106989
89. Zhao, QL, Huang, YC, and Li, CN. Does adolescents' internet addiction trigger depressive symptoms and aggressive behavior, or vice versa? The moderating roles of peer relationships and gender. Comput Hum Behav. (2022) 129:107143. doi: 10.1016/j.chb.2021.107143
90. Xiao, J, Liang, K, Huang, L, Wang, E, Huang, Q, He, Y, et al. The cumulative effects, relationship model, and the effects of specific positive development assets in reducing adolescent depression. Psychol Dev Educ. (2024) 40:257–69. doi: 10.16187/j.cnki.issn1001-4918.2024.02.13
91. Theokas, C, and Lerner, RM. Observed ecological assets in families, schools, and neighborhoods: conceptualization, measurement, and relations with positive and negative developmental outcomes. Appl Dev Sci. (2006) 10:61–74. doi: 10.1207/s1532480xads1002_2
92. Pérez-González, A, Guilera, G, Pereda, N, and Jarne, A. Protective factors promoting resilience in the relation between child sexual victimization and internalizing and externalizing symptoms. Child Abuse Negl. (2017) 72:393–403. doi: 10.1016/j.chiabu.2017.09.006
93. Chi, XL, and Cui, XM. Externalizing problem behaviors among adolescents in a southern city of China: gender differences in prevalence and correlates. Child Youth Serv Rev. (2020) 119:105632. doi: 10.1016/j.childyouth.2020.105632
94. Gestsdottir, S, Geldhof, GJ, Lerner, JV, and Lerner, RM. What drives positive youth development? Assessing intentional self-regulation as a central adolescent asset. Int J Dev Sci. (2017) 11:69–79. doi: 10.3233/DEV-160207
95. Wang, Z, Hong, BX, Zhang, YY, Su, Y, Li, MH, Zhao, L, et al. Children and adolescents' positive youth development qualities and internet addiction during the COVID-19 pandemic: a longitudinal study in China. Front Psych. (2023) 13:1068737. doi: 10.3389/fpsyt.2022.1068737
96. Atkiss, K, Moyer, M, Desai, M, and Roland, M. Positive youth development: an integration of the developmental assets theory and the socio-ecological model. Am J Health Educ. (2011) 42:171–80. doi: 10.1080/19325037.2011.10599184
97. Chi, X, Liu, X, Huang, Q, Cui, X, and Lin, L. The relationship between positive youth development and depressive symptoms among Chinese early adolescents: a three-year cross-lagged analysis. Int J Environ Res Public Health. (2020) 17:404. doi: 10.3390/ijerph17176404
98. Wang, E, Zhang, J, Huang, Q, Huang, L, Liang, K, Jiang, W, et al. The relationship between family functioning and behavior problems in adolescents: a cross-lagged study. Chin J Clin Psych. (2022) 30:794–801. doi: 10.16128/j.cnki.1005-3611.2022.04.009
99. Aponte Rueda, DR, Castillo Chávez, P, and González Estrella, JE. Prevalence of internet addiction and its relation to family dysfunction in adolescents. Revista Clínica de Medicina de Familia. (2017) 10:179–86.
100. Ko, CH, Wang, PW, Liu, TL, Yen, CF, Chen, CS, and Yen, JY. Bidirectional associations between family factors and internet addiction among adolescents in a prospective investigation. Psychiatry Clin Neurosci. (2015) 69:192–200. doi: 10.1111/pcn.12204
101. Yen, JY, Yen, CF, Chen, CC, Chen, SH, and Ko, CH. Family factors of internet addiction and substance use experience in Taiwanese adolescents. Cyberpsychol Behav. (2007) 10:323–9. doi: 10.1089/cpb.2006.9948
102. Zhang, J, and Wang, E. Combined effect of family care and class belonging on internet addiction in vocational college students with left-behind experience in Henan province. Med Soc. (2022) 35:124–9. doi: 10.13723/j.yxysh.2022.07.023
103. Chi, X, Huang, L, Wang, J, and Zhang, P. The prevalence and socio-demographic correlates of depressive symptoms in early adolescents in China: differences in only child and non-only child groups. Int J Environ Res Public Health. (2020) 17:438. doi: 10.3390/ijerph17020438
104. Qin, X, Kaufman, T, Laninga-Wijnen, L, Ren, P, Zhang, Y, and Veenstra, R. The impact of academic achievement and parental practices on depressive symptom trajectories among Chinese adolescents. Res Child Adolesc Psychopathol. (2021) 49:1359–71. doi: 10.1007/s10802-021-00826-9
105. Ko, C-H, Liu, T-L, Wang, P-W, Chen, C-S, Yen, C-F, and Yen, J-Y. The exacerbation of depression, hostility, and social anxiety in the course of internet addiction among adolescents: a prospective study. Compr Psychiatry. (2014) 55:1377–84. doi: 10.1016/j.comppsych.2014.05.003
106. Li, Y, Zhang, X, Lu, F, Zhang, Q, and Wang, Y. Internet addiction among elementary and middle school students in China: a nationally representative sample study. Cyberpsychol Behav Soc Netw. (2014) 17:111–6. doi: 10.1089/cyber.2012.0482
107. Lewis, AJ, Kremer, P, Douglas, K, Toumborou, JW, Hameed, MA, Patton, GC, et al. Gender differences in adolescent depression: differential female susceptibility to stressors affecting family functioning. Aust J Psychol. (2015) 67:131–9. doi: 10.1111/ajpy.12086
108. Liang, L, Zhou, D, Yuan, C, Shao, A, and Bian, Y. Gender differences in the relationship between internet addiction and depression: a cross-lagged study in Chinese adolescents. Comput Hum Behav. (2016) 63:463–70. doi: 10.1016/j.chb.2016.04.043
109. Park, S, Hong, KEM, Park, EJ, Ha, KS, and Yoo, HJ. The association between problematic internet use and depression, suicidal ideation and bipolar disorder symptoms in Korean adolescents. Aust N Z J Psychiatry. (2013) 47:153–9. doi: 10.1177/0004867412463613
110. Cannito, L, Ceccato, I, Annunzi, E, Bortolotti, A, D'Intino, E, Palumbo, R, et al. Bored with boredom? Trait boredom predicts internet addiction through the mediating role of attentional bias toward social networks. Front Hum Neurosci. (2023) 17:1179142. doi: 10.3389/fnhum.2023.1179142
Keywords: joint trajectories, Internet addiction, depressive symptoms, adolescents, longitudinal study
Citation: Zhang J, Wang E, Zhang L and Chi X (2024) Internet addiction and depressive symptoms in adolescents: joint trajectories and predictors. Front. Public Health. 12:1374762. doi: 10.3389/fpubh.2024.1374762
Edited by:
Ashwani Kumar Mishra, All India Institute of Medical Sciences, IndiaReviewed by:
Zeyang Yang, Soochow University, ChinaStefania Mancone, University of Cassino, Italy
Loreta Cannito, University of Foggia, Italy
Copyright © 2024 Zhang, Wang, Zhang and Chi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Long Zhang, SDIxMDkyMTAwMDkzQGNpdHl1Lm1v; Xinli Chi, eGlubGljaGlAc3p1LmVkdS5jbg==
†These authors have contributed equally to this work