John TullyIntroduction
Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder, estimated to affect 5–7% of children and adolescents worldwide [(1–3), though see (4, 5)]. ADHD was once thought to decline rapidly with age, with persistence into adulthood thought to be very uncommon (6). In the last two decades, thinking has shifted (7). While estimates for persistence into adulthood vary, more robust research studies suggest this is about 15% (8). Widely cited studies estimate the prevalence of adult ADHD in the general population to be 3–5% (9–11), with rates typically being higher for men, though concerns about overdiagnosis should be noted (5, 12–14). Increasing awareness and discussion about ADHD has led to development of several consensus and guidance documents internationally (15–21). In incarcerated populations, rates are thought to be disproportionately high (22), but underdiagnosed (23), leading to lobbying for prioritization of ADHD in prisons and calls for effective screening and treatment protocols (20–25).
Increased recognition and treatment of ADHD in adult prisoners has several potential benefits, beyond improvements in subjective well-being. Firstly, for many patients, receiving a diagnosis of ADHD may be validating (26). It could feasibly allow prisoners to come to terms with their offending histories and accept input from mental health services, which may in turn identify other mental health problems. Secondly, if treatment proves effective, resolution of core symptoms of the condition may encourage attendance at educational, occupational and therapeutic activities (25), which can have broader clinical benefits (27). Thirdly, if links between ADHD symptomatology and problematic behaviors within prisons, especially violence, are shown to exist, effective treatments would reduce the burden of these behaviors on prisons. Finally, as effective treatments for the most common cause of aggression and violence in prisoners—antisocial personality disorder (ASPD)—are very limited (28, 29), reattribution of some antisocial behavior to ADHD may have benefits to staff in mental health settings, reducing the therapeutic nihilism that is associated with ASPD (30, 31).
Efforts to improve outcomes for prisoners' mental health and reduce violence and offending are welcome. However, there are several reasons for caution toward the emergent focus on ADHD, and several gaps in the evidence base that need to be addressed. Below, I outline these in turn, offering suggestions for a measured and empirical approach to the condition within holistic formulation and management in prison psychiatry settings.
Uncertainty About the Scale of the Problem in Prisons
Until recently, estimates of prevalence of ADHD in incarcerated populations varied so widely—from 4 to 72% (32)—as to resist meaningful interpretation. Hence, a 2015 meta-analysis of studies in prison populations (22) was beneficial. This found an overall prevalence of ADHD of 25.5% (26.2% in adult prisoners; no significant difference by sex) using diagnostic interviews.
This meta-analysis also revealed wide geographical variation in estimates, from 6.6% in Brazil (33) to 65.2% in Sweden (22). This could possibly be explained by differences in quality of assessments. Notably, studies included that used screening for diagnosis had a significantly higher estimated ADHD prevalence of 43.3% [though see (34)]. However, while a prevalence of about 25% was supported by a subsequent study in a Scottish prison using a structured interview (35), other high quality individual studies in male prisoners in Canada and France, using rigorous assessment protocols, report considerably lower prevalence rates of 17% (32) and 11% (36), respectively. These discrepancies may be explained in part by differential clinical profiles of prisoners between countries with large variation in sociodemographic profiles, though this explanation is perhaps less convincing for significant variation in rates between, for example, Scotland and France. It is also not clear to what extent a diagnosis of adult ADHD equates to clinically relevant symptomatology. A study in another Scottish prison (37) found a rate of 24% meeting criteria for ADHD in childhood, but only 23% of this subgroup (5.5% of the total sample) were fully symptomatic in adulthood at the time of the study (the study did not report how many were on treatment).
Overall, existing studies of prevalence ADHD in prisons continue to show considerable variation, even where more detailed assessments and stricter application of criteria are applied. Furthermore, receiving a diagnosis of ADHD does not necessarily equate to clinically relevant symptomatology. Together, this suggests ongoing caution is warranted in estimating the clinical impact of ADHD in any given prison population, and the need for ongoing rigorous assessments at national and local levels. As other authors have highlighted, inflated estimates of ADHD in prisons also risks stigmatizing individuals with ADHD in the general population as excessively prone to criminal behavior (38).
Disproportionate use of Resources
A major shift in focus toward assessing and treating ADHD in prison risks a disproportionate approach to prison healthcare. Other mental disorders are very common in prisoners (39), with much higher rates of major depression (10–14%) and psychotic illness (4%) than in the general population (40, 41), and higher rates still in low and middle income countries (42). Substance misuse disorders are also very common (39, 43, 44), as high as 85% for male remand and 78% for male sentenced prisoners (43). Personality disorders are especially common, with estimates of 65% for any personality disorder and 47% for ASPD from a large-scale analysis (40). Borderline personality disorder [or emotionally unstable personality disorder (EUPD)] has been more commonly studied in female prisoners, with rates of about 25% (40), but may be similarly high in male prisoners (45). There are high rates of self-harm (46) and suicide (47, 48), which though linked to ADHD in general population (49), are strongly associated with personality disorders, depression, substance misuse, and psychosis (50–56), and of violence (57–59), which is especially associated with ASPD (56, 60–65). Despite this, prison mental health services remain chronically under-resourced (66), with substantial delays in transfer to hospital for treatment in most countries where data is reported (67–70), and limited access to and study of psychosocial and follow-up interventions that may be effective (27).
In this context, resources must be used judiciously, and proportionate to clinical need, in keeping with both standard procedures for allocation of community resources and the equivalence principle for prison healthcare (71). However, assessment of adult ADHD in accordance with good practice guidelines is heavily resource-intensive (16, 38). As ADHD is a neurodevelopmental disorder, therefore arising in childhood, confirmation of its presence in childhood and adolescence is essential to making a confident diagnosis of ADHD in adulthood. Yet confirmation of a diagnosis is often not available, requiring collation of collateral information from childhood. Additionally, in part due to concerns about drug-seeking and malingering of symptoms, good practice guidelines for adult ADHD (16, 17) appropriately call for a diagnostic assessment for adults, such as the DIVA (72), to be carried out, which takes a further 1.5 h. Assessments of adult ADHD therefore take significant additional time and resources, compared to assessment of common acute psychiatric presentations. This places further considerable pressures on mental health services in prisons. In the UK, guidance from the Royal College of Psychiatrists clearly states that ADHD is not an emergency (16), however in the clinical setting, services are coming under increasing pressure to rapidly assess and treat ADHD. For instance, a recent consensus statement highlights that “[commissioning groups] and clinicians are potentially at risk of being challenged if they ignore NICE Guidance and they should only do that if they have something better to offer” (20). Clinical teams must be apportioned reasonable timeframes to carry out assessments, and these should be aligned with available resources and the acute clinical need of other patients.
Misattribution of Problem Behaviors
Excessive focus on ADHD may lead to misattribution of problematic behaviors. The large majority of individuals with ADHD do not offend (73). In those that do, a very high proportion have comorbid mental disorders. A meta-analysis demonstrated that in adult prisoners with ADHD, substance misuse disorders were comorbid in 74% of cases and personality disorders in 60% (74). A further selective review suggested the rate of comorbid mental disorder is as high as 96% (75). A broad interpretation of these figures would therefore suggest that it is these comorbid conditions, possibly alongside psychosocial factors, that would account for most of the offending in people with ADHD. This is supported by studies demonstrating no association between ADHD and criminal behavior when controlling for comorbid conditions such as conduct disorder and antisocial personality disorder [(76–79), although see (80, 81)], and a large epidemiological study of study in young people aged 16–24 demonstrating that the relationship between ADHD symptoms and offending among young people is largely explained indirectly by comorbid factors (77). Furthermore, the association between ADHD and criminality is reduced or eliminated with adjustment for lifetime substance use disorders (82, 83).
Despite this, a recurring theme in existing literature is the attribution of antisocial behavior in prisoners to ADHD. For instance, one editorial suggests that ADHD is “a major causal risk factor for the development of criminal behavior” (84). Another paper states that “the reasons for the particularly high rates of behavioral disturbance [in prisoners] with ADHD are likely to stem from several sources related to the core syndrome of ADHD, including impulsive responding, mood instability, emotional dysregulation and low frustration tolerance” (24). Yet emotional dysregulation is classified by DSM-5 only as an associated feature of ADHD, not a diagnostic specifier (15, 85). In contrast, it is a long-established core symptom of EUPD (borderline) personality disorder, which is present in up to 30% of prisoners (45). Despite theoretical explanations (86), whether the type of emotional dysregulation seen in ADHD is qualitatively different to that seen in EUPD or other disorders remains unclear (15). This raises the possibility that when emotional dysregulation is present in individuals with ADHD, it is mostly or always due to EUPD or other comorbid conditions, and not related to ADHD.
Likewise, aggression is not a diagnostic feature of ADHD. DSM-5 criteria for ADHD specify impulsive behaviors such as interrupting, blurting out answers, and difficulty waiting one's turn—not aggression or violence (85). In contrast, a low threshold for discharge of aggression, associated with impulsivity and low tolerance of frustration, is a core component of ASPD (87)—present in 47% of prisoners (40) and accounting for the large majority of violent crime in society (88–90). While plausible accounts of potential mechanistic links between ADHD and aggression and violence have been put forward (91–95), these remain theoretical. Notably, a meta-analysis investigating the neural underpinnings of cold and hot executive dysfunction in youth with disruptive behavior disorders (precursors of ASPD) found structural and functional deficits in relevant neural circuitry which were present irrespective of the presence of ADHD comorbidity (96). Hence, where antisocial behaviors, or traits, are present in prisoners with ADHD, they cannot be assumed to be due to ADHD.
In particular, to properly disentangle the relative contributions of ADHD and ASPD to violence and aggression in prisoners, there is a need for studies comparing those with ADHD and comorbid ASPD (ADHD+ASPD) to those with ADHD-only, and ideally, also those with ASPD-only, and healthy controls with neither condition. No such study has been carried out in adult prisoners. One study in a Scottish prison (37) showed that a small subsample of prisoners who were fully symptomatic or in partial remission for ADHD (10 ADHD-only, 17 ADHD+ASPD), were significantly more aggressive and functionally impaired than prisoners who were symptom free (103 no ADHD/ASPD, 68 with ASPD), after controlling for ASPD, using a sequential binomial logistic regression. However, no direct comparisons between ADHD-only, ADHD+ASPD, or ASPD-only were reported, and diagnosis of ASPD relied on MCMI profiles rather than a more rigorous assessment such as DSM criteria. In sum, the contribution of ADHD to aggression and violence over and above ASPD in prisoners has not been convincingly demonstrated to date, and should not be assumed to exist. As one of the arguments for treating ADHD in prisoners is reducing risk of aggression and violence (25), this must be factored into risk: benefit decisions about treatment.
Unrealistic Expectations of Treatment
While expert guidelines state that the treatment of adults with ADHD should follow a multimodal approach, including psychoeducation and cognitive behavior therapy (15, 16), medication is now the first-line treatment for adults with ADHD (16, 17, 97). However, evidence for prescribing of stimulant and other medication in ADHD has been fraught with inconsistencies (98, 99) and beset by controversy (5, 100–102). Several meta-analyses have highlighted problems including lack of evidence for long-term effects, considerable incidence of adverse events, high risk of bias, and low to very low quality of evidence in studies of ADHD medications in both youths and adults (103–105). One meta-analysis found a poor benefit–risk balance for atomoxetine in adults with ADHD (106). Two other meta-analyses in adults (98, 99) showed no association between dose and efficacy of ADHD medications, raising questions about their mechanistic basis. The recommendation of medication as a first-line treatment for adult ADHD in the general population was made based on three randomized controlled trials, two of which were conducted by a group who came under investigation for undeclared conflict of interests (101). One Cochrane review—on immediate-release methylphenidate for adult ADHD (107)—was withdrawn in 2016 after substantial criticism of its methods and flawed conclusions (100). Taken together, this does not provide a clear-cut basis for prescribing medication in adult ADHD.
A more recent network meta-analysis (98) provided some support for use of stimulants, atomoxetine, and bupropion in adult ADHD. There were caveats however: evidence was found for short-term (12 weeks) effects only, there was a wide confidence interval (−0.99 to −0.58) for amphetamines, and medications were less efficacious and less well-tolerated in adults than in children and adolescents. Critically, trials in which participants had a comorbid disorder treated with non-ADHD medication were excluded (98). Given the high rates of mental disorder (40, 41) and use of psychotropic medication (108, 109) in prisoners, this undermines the generalisability of these findings to prisoners with adult ADHD. One randomized controlled trial provided evidence of improved global functioning following treatment with methylphenidate in prisoners with ADHD, though in a very small sample (n = 15 in treatment and placebo groups) and for a very short blinded observation period of 5 weeks (110). Another small RCT (111), in which outcomes in both placebo and treatment groups may have been confounded by simultaneous CBT, demonstrated reduced self-rated symptoms with methylphenidate compared to placebo, though no significant difference in clinician-rated improvement on CGI-I.
Taken together, existing trial data does not provide strong support for use of medications for ADHD in adult prisoners. Conduct of RCTs in prisons is especially challenging. An alternative to RCTs is pharmacoepidemiological studies, which allow evaluation of population-wide effects of medications. Evidence from one such large scale study based on Swedish registries of released prisoners (108) found a reduction in violent offending in those dispensed psychostimulants, though with a very wide confidence interval (within-individual hazard ratio 0.62, 95% CI 0.40–0.98). Another demonstrated significant reductions in the criminality rate in both men (32%) and women (41%), though sensitivity analyses (limited to men) showed that the rate reduction varied considerably (17 to 46%) depending on type of drug and type of outcome (112). Though the problem of confounding effects may be overcome with careful study design and appropriate sensitivity analyses, pharmacoepidemiological studies cannot cannot account for all possible confounders that select individuals to treatment and cannot prove causality. Validation with multiple samples and triangulation with other designs have been identified as a necessity (108). In particular, the absence of good evidence from adequately powered RCTs remains a concern, as has been repeatedly highlighted by NICE (18, 113). At least one such preregistered trial is now underway in the UK (113). This level of evidence is required to justify use of these medications as first-line interventions, the risks of which are discussed below.
Risks of Prescribing
The risks of prescribing ADHD medication in prisoners are not trivial. Common or very common side-effects of methylphenidate and/or atomoxetine include aggression or hostility, anxiety/feeling jittery, abnormal behavior, depression and alterations in mood, and sleep disorders (114). This should be of particular concern in a population of patients with high baseline rates of all of these problems. Common or very common physical side-effects include arrhythmias, arthralgia, gastrointestinal disturbance, hypertension, and movement disorders (114). These risks are compounded by much poorer than average physical health in prisoners (115, 116). Furthermore, as many prisoners with adult ADHD will be treated with medications for comorbid conditions, potential drug-drug interactions must be considered (15). These include interactions between methylphenidate or atomoxetine and CYP 2D6 enzyme inhibitors such as fluoxetine, and increased risk of hypertension and other cardiovascular events through co-prescribing of agents such as duloxetine or venlafaxine (117).
Another important consideration is misuse of medication. Although modified-release formulations of stimulant medications are thought to reduce risk of misuse (118), all formulations carry a high risk for abuse and dependence if not used as prescribed (117). This is particularly important in prisoners, many of whom have extensive histories of substance misuse. Interaction of stimulants with other illicit drugs is also concerning. Illicit drugs remain a significant problem in prisons internationally (119–121), with synthetic cannabinoids (e.g., “Spice” and “Mamba”) a particularly troublesome issue in UK prisons (121, 122). Potential interactions of stimulants with other illicit drugs include a toxic sympathomimetic syndrome with prominent cardiac and neurological effects (123, 124). Evidence in human studies is mostly limited to a handful of small studies focused mainly on simultaneous use of alcohol (125), though one RCT showed that the hemodynamic and adverse effects of co-administration of methylphenidate and MDMA were significantly higher compared with MDMA or methylphenidate alone (126). It has been hypothesized that by reducing impulsivity and individuals' tendency to self-medicate, and addressing underlying mechanisms associated with addiction pathways, stimulant medication may help to protect against illicit substance use (23). However, such an effect in prison populations has not been demonstrated beyond a single small study, which was potentially confounded by simultaneous CBT (111). Notably, in meta-analysis in a general population sample, ADHD medications had no beneficial effect on drug abstinence (127). Diversion of prescribed stimulants—present in up to 80% of community samples (128)—is a further important consideration in prisons, where diversion and trading of many psychotropic medications remains a substantial problem (129, 130).
In sum, these findings provide reason for considerable caution in prescribing ADHD medications in prisoners. It has been suggested that not offering medication to prisoners with ADHD may be ethically questionable (131). However, the same is certainly true for providing any treatment to a vulnerable clinical population based on limited or substandard evidence, without due consideration of risks. These risks must be meaningfully weighed against potential benefits in all prescribing decisions.
Conclusions
A focus on ADHD in prisoners has emerged in the last decade, with concerns that the condition is under-recognized and undertreated in prisons. Calls for a shift in emphasis toward ADHD are likely driven in part by exasperation with lack of effective treatments for other disorders, especially ASPD, which is exceptionally common in prisoners. There is much enthusiasm for developing new assessment and treatment pathways, alongside optimism that this will result in significant improvements in outcomes. To date, however, the evidence base to support all of this is very limited. Questions remain about the true prevalence of ADHD in prisoners, and the extent to which diagnosis equates with clinically relevant symptomatology. Particular concerns surround lack of evidence for mechanistic links between ADHD and antisocial behavior, misidentification of ADHD as a contributory cause of violence, inconsistent evidence for ADHD medication in adults generally (and almost no high quality evidence in prisoners), lack of cost-benefit analysis for interventions, and insufficient risk: benefit considerations in prescribing guidelines. To bridge these gaps, ongoing studies using robust assessment protocols are required to get a more accurate and granular understanding of rates on ADHD in specific prison populations. Randomized controls trials are required to support use of medication for ADHD as a first-line treatment. Importantly, given the prevalence of other mental disorders with direct links to self-harm, suicide, and violence, well-intentioned initiatives should not be allowed to create a disproportionate and misguided focus on ADHD as a primary problem in prison mental healthcare. Until a better standard of evidence exists, its status is more appropriately considered as under ongoing review.
Author Contributions
The author confirms being the sole contributor of this work and has approved it for publication.
Conflict of Interest
The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
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References
1. Polanczyk GV, Willcutt EG, Salum GA, Kieling C, Rohde LA. ADHD prevalence estimates across three decades: an updated systematic review and meta-regression analysis. Int J Epidemiol. (2014) 43:434–42. doi: 10.1093/ije/dyt261
2. Thomas R, Sanders S, Doust J, Beller E, Glasziou P. Prevalence of attention-deficit/hyperactivity disorder: a systematic review and meta-analysis. Pediatrics. (2015) 135:e994–1001. doi: 10.1542/peds.2014-3482
3. Willcutt EG. The prevalence of DSM-IV attention-deficit/hyperactivity disorder: a meta-analytic review. Neurotherapeutics. (2012) 9:490–9. doi: 10.1007/s13311-012-0135-8
4. Wang L-J, Lee S-Y, Yuan S-S, Yang C-J, Yang K-C, Huang T-S, et al. Prevalence rates of youths diagnosed with and medicated for ADHD in a nationwide survey in Taiwan from 2000 to 2011. Epidemiol Psychiatr Sci. (2017) 26:624–34. doi: 10.1017/S2045796016000500
5. Paris J, Bhat V, Thombs B. Is adult attention-deficit hyperactivity disorder being overdiagnosed? Can J Psychiatry. (2015) 60:324–8. doi: 10.1177/070674371506000705
6. Hill JC, Schoener EP. Age-dependent decline of attention deficit hyperactivity disorder. Am J Psychiatry. (1996) 153:1143–6.
7. Asherson P, Adamou M, Bolea B, Muller U, Morua SD, Pitts M, et al. Is ADHD a valid diagnosis in adults? Yes. BMJ. (2010) 340:c549. doi: 10.1136/bmj.c549
8. Faraone SV, Biederman J. What is the prevalence of adult ADHD? Results of a population screen of 966 adults. J Attent Disord. (2005) 9:384–91. doi: 10.1177/1087054705281478
9. Fayyad J, De Graaf R, Kessler R, Alonso J, Angermeyer M, Demyttenaere K, et al. Cross-national prevalence and correlates of adult attention-deficit hyperactivity disorder. Br J Psychiatry. (2007) 190:402–9. doi: 10.1192/bjp.bp.106.034389
10. Simon V, Czobor P, Bálint S, Mészáros A, Bitter I. Prevalence and correlates of adult attention-deficit hyperactivity disorder: meta-analysis. Br J Psychiatry. (2009) 194:204–11. doi: 10.1192/bjp.bp.107.048827
11. Kessler RC, Adler L, Barkley R, Biederman J, Conners CK, Demler O, et al. The prevalence and correlates of adult ADHD in the United States: results from the National Comorbidity Survey Replication. Am J Psychiatry. (2006) 163:716–23. doi: 10.1176/ajp.2006.163.4.716
12. Batstra L, Frances A. DSM-5 further inflates attention deficit hyperactivity disorder. J Nerv Ment Dis. (2012) 200:486–8. doi: 10.1097/NMD.0b013e318257c4b6
13. Woloshin S, Kramer B. Overdiagnosis: it's official. BMJ. (2021) 375:n2854. doi: 10.1136/bmj.n2854
14. Haslam N. Concept creep: psychology's expanding concepts of harm and pathology. Psychol Inq. (2016) 27:1–17. doi: 10.1080/1047840X.2016.1082418
15. Kooij J, Bijlenga D, Salerno L, Jaeschke R, Bitter I, Balazs J, et al. Updated European Consensus Statement on diagnosis and treatment of adult ADHD. Eur Psychiatry. (2019) 56:14–34. doi: 10.1016/j.eurpsy.2018.11.001
17. National Guideline Centre UK. Attention Deficit Hyperactivity Disorder: Diagnosis and Management (2018).
18. National Collaborating Centre for Mental Health NICE. Attention Deficit Hyperactivity Disorder: Diagnosis and Management of ADHD in Children, Young People and Adults (2009).
19. Hope P, Hanson D, Coaker V, Ward C. Improving Health, Supporting Justice: The National Delivery Plan of the Health and Criminal Justice Programme Board. London: Department of Health (2009).
20. Young S, Asherson P, Lloyd T, Absoud M, Arif M, Colley WA, et al. Failure of healthcare provision for attention-deficit/hyperactivity disorder in the United Kingdom: a consensus statement. Front Psychiatry. (2021) 12:324. doi: 10.3389/fpsyt.2021.649399
21. Young S, Gudjonsson G, Chitsabesan P, Colley B, Farrag E, Forrester A, et al. Identification and treatment of offenders with attention-deficit/hyperactivity disorder in the prison population: a practical approach based upon expert consensus. BMC Psychiatry. (2018) 18:1–16. doi: 10.1186/s12888-018-1858-9
22. Young S, Moss D, Sedgwick O, Fridman M, Hodgkins P. A meta-analysis of the prevalence of attention deficit hyperactivity disorder in incarcerated populations. Psychol Med. (2015) 45:247–58. doi: 10.1017/S0033291714000762
23. Young S, Cocallis KM. Attention Deficit Hyperactivity Disorder (ADHD) in the prison system. Curr Psychiatry Rep. (2019) 21:1–9. doi: 10.1007/s11920-019-1022-3
24. Young SJ, Adamou M, Bolea B, Gudjonsson G, Müller U, Pitts M, et al. The identification and management of ADHD offenders within the criminal justice system: a consensus statement from the UK Adult ADHD Network and criminal justice agencies. BMC Psychiatry. (2011) 11:1–14. doi: 10.1186/1471-244X-11-32
25. Young S, Goodwin E. Attention-deficit/hyperactivity disorder in persistent criminal offenders: the need for specialist treatment programs. Expert Rev Neurother. (2010) 10:1497–500. doi: 10.1586/ern.10.142
26. Halleröd SLH, Anckarsäter H, Råstam M, Scherman MH. Experienced consequences of being diagnosed with ADHD as an adult–a qualitative study. BMC Psychiatry. (2015) 15:1–13. doi: 10.1186/s12888-015-0410-4
27. Beaudry G, Yu R, Perry AE, Fazel S. Effectiveness of psychological interventions in prison to reduce recidivism: a systematic review and meta-analysis of randomised controlled trials. Lancet Psychiatry. (2021) 8:759–73. doi: 10.1016/S2215-0366(21)00170-X
28. Gibbon S, Khalifa NR, Cheung NH, Völlm BA, McCarthy L. Psychological interventions for antisocial personality disorder. Cochrane Database Syst Rev. (2020) 9:CD007668. doi: 10.1002/14651858.CD007668.pub3
29. Khalifa NR, Gibbon S, Völlm BA, Cheung NH, McCarthy L. Pharmacological interventions for antisocial personality disorder. Cochrane Database Syst Rev. (2020) 9:CD007667. doi: 10.1002/14651858.CD007667.pub3
30. Yakeley J, Williams A. Antisocial personality disorder: new directions. Adv Psychiatr Treat. (2014) 20:132–43. doi: 10.1192/apt.bp.113.011205
31. Felthous AR. The “untreatability” of psychopathy and hospital commitment in the USA. Int J Law Psychiatry. (2011) 34:400–5. doi: 10.1016/j.ijlp.2011.10.004
32. Usher AM, Stewart LA, Wilton G. Attention deficit hyperactivity disorder in a Canadian prison population. Int J Law Psychiatry. (2013) 36:311–5. doi: 10.1016/j.ijlp.2013.04.005
33. Pondé MP, Freire AC, Mendonça MS. The prevalence of mental disorders in prisoners in the city of Salvador, Bahia, Brazil. J Forensic Sci. (2011) 56:679–82. doi: 10.1111/j.1556-4029.2010.01691.x
34. Baggio S, Fructuoso A, Guimaraes M, Fois E, Golay D, Heller P, et al. Prevalence of attention deficit hyperactivity disorder in detention settings: a systematic review and meta-analysis. Front Psychiatry. (2018) 9:331. doi: 10.3389/fpsyt.2018.00331
35. Young S, González RA, Mutch L, Mallet-Lambert I, O'rourke L, Hickey N, et al. Diagnostic accuracy of a brief screening tool for attention deficit hyperactivity disorder in UK prison inmates. Psychol Med. (2016) 46:1449–58. doi: 10.1017/S0033291716000039
36. Gaïffas A, Galéra C, Mandon V, Bouvard MP. Attention-deficit/hyperactivity disorder in young french male prisoners. J Forensic Sci. (2014) 59:1016–9. doi: 10.1111/1556-4029.12444
37. Young S, Gudjonsson GH, Wells J, Asherson P, Theobald D, Oliver B, et al. Attention deficit hyperactivity disorder and critical incidents in a Scottish prison population. Pers Individ Dif. (2009) 46:265–9. doi: 10.1016/j.paid.2008.10.003
38. Murphy K, Appelbaum K. How reliable are prevalence rates of ADHD in prisons? ADHD Rep. (2017) 25:1–5. doi: 10.1521/adhd.2017.25.2.1
39. Fazel S, Hayes AJ, Bartellas K, Clerici M, Trestman R. Mental health of prisoners: prevalence, adverse outcomes, and interventions. Lancet Psychiatry. (2016) 3:871–81. doi: 10.1016/S2215-0366(16)30142-0
40. Fazel S, Danesh J. Serious mental disorder in 23 000 prisoners: a systematic review of 62 surveys. Lancet. (2002) 359:545–50. doi: 10.1016/S0140-6736(02)07740-1
41. Fazel S, Seewald K. Severe mental illness in 33 588 prisoners worldwide: systematic review and meta-regression analysis. Br J Psychiatry. (2012) 200:364–73. doi: 10.1192/bjp.bp.111.096370
42. Baranyi G, Scholl C, Fazel S, Patel V, Priebe S, Mundt AP. Severe mental illness and substance use disorders in prisoners in low-income and middle-income countries: a systematic review and meta-analysis of prevalence studies. Lancet Global Health. (2019) 7:e461–71. doi: 10.1016/S2214-109X(18)30539-4
43. Singleton N, Farrell M, Meltzer H. Substance misuse among prisoners in England and Wales. Int Rev Psychiatry. (2003) 15:150–2. doi: 10.1080/0954026021000046092
44. Fazel S, Bains P, Doll H. Substance abuse and dependence in prisoners: a systematic review. Addiction. (2006) 101:181–91. doi: 10.1111/j.1360-0443.2006.01316.x
45. Black DW, Gunter T, Allen J, Blum N, Arndt S, Wenman G, et al. Borderline personality disorder in male and female offenders newly committed to prison. Compr Psychiatry. (2007) 48:400–5. doi: 10.1016/j.comppsych.2007.04.006
46. Favril L, Yu R, Hawton K, Fazel S. Risk factors for self-harm in prison: a systematic review and meta-analysis. Lancet Psychiatry. (2020) 7:682–91. doi: 10.1016/S2215-0366(20)30190-5
47. Fazel S, Ramesh T, Hawton K. Suicide in prisons: an international study of prevalence and contributory factors. Lancet Psychiatry. (2017) 4:946–52. doi: 10.1016/S2215-0366(17)30430-3
48. Fazel S, Grann M, Kling B, Hawton K. Prison suicide in 12 countries: an ecological study of 861 suicides during 2003–2007. Soc Psychiatry Psychiatr Epidemiol. (2011) 46:191–5. doi: 10.1007/s00127-010-0184-4
49. Septier M, Stordeur C, Zhang J, Delorme R, Cortese S. Association between suicidal spectrum behaviors and Attention-Deficit/Hyperactivity Disorder: a systematic review and meta-analysis. Neurosci Biobehav Rev. (2019) 103:109–18. doi: 10.1016/j.neubiorev.2019.05.022
50. Baillargeon J, Penn JV, Thomas CR, Temple JR, Baillargeon G, Murray OJ. Psychiatric disorders and suicide in the nation's largest state prison system. J Am Acad Psychiatry Law Online. (2009) 37:188–93. Available online at: http://www.antoniocasella.eu/salute/Baillargeon_suicide_prisons_2009.pdf
51. Way BB, Miraglia R, Sawyer DA, Beer R, Eddy J. Factors related to suicide in New York state prisons. Int J Law Psychiatry. (2005) 28:207–21. doi: 10.1016/j.ijlp.2004.09.003
52. Lupei RA. Jail Suicides: Demographic and Behavioral Factors Postdictive of the Completed Act. Ann Arbor: Oklahoma State University (1981).
53. Rivlin A, Hawton K, Marzano L, Fazel S. Psychiatric disorders in male prisoners who made near-lethal suicide attempts: case–control study. Br J Psychiatry. (2010) 197:313–9. doi: 10.1192/bjp.bp.110.077883
54. Marzano L, Fazel S, Rivlin A, Hawton K. Psychiatric disorders in women prisoners who have engaged in near-lethal self-harm: case–control study. Br J Psychiatry. (2010) 197:219–26. doi: 10.1192/bjp.bp.109.075424
55. Hawton K, Linsell L, Adeniji T, Sariaslan A, Fazel S. Self-harm in prisons in England and Wales: an epidemiological study of prevalence, risk factors, clustering, and subsequent suicide. Lancet. (2014) 383:1147–54. doi: 10.1016/S0140-6736(13)62118-2
56. Black DW, Gunter T, Loveless P, Allen J, Sieleni B. Antisocial personality disorder in incarcerated offenders: psychiatric comorbidity and quality of life. Ann Clin Psychiatry. (2010) 22:113–20. Available online at: https://www.academia.edu/download/79492022/Black_aspd_2010.pdf
59. BBC. Prison Assaults in England and Wales at Record High. (2019). Available online at: https://www.bbc.co.uk/news/uk-47070713
60. Azevedo J, Vieira-Coelho M, Castelo-Branco M, Coelho R, Figueiredo-Braga M. Impulsive and premeditated aggression in male offenders with antisocial personality disorder. PLoS ONE. (2020) 15:e0229876. doi: 10.1371/journal.pone.0229876
61. Hare RD, McPherson LM. Violent and aggressive behavior by criminal psychopaths. Int J Law Psychiatry. (1984) 7:35–50. doi: 10.1016/0160-2527(84)90005-0
62. Warren JI, Burnette M, South SC, Chauhan P, Bale R, Friend R. Personality disorders and violence among female prison inmates. J Am Acad Psychiatry Law Online. (2002) 30:502–9. Available online at: https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.1064.1241&rep=rep1&type=pdf
63. Yu R, Geddes JR, Fazel S. Personality disorders, violence, and antisocial behavior: a systematic review and meta-regression analysis. J Pers Disord. (2012) 26:775–92. doi: 10.1521/pedi.2012.26.5.775
64. Blackburn R, Coid JW. Empirical clusters of DSM-III personality disorders in violent offenders. J Pers Disord. (1999) 13:18–34. doi: 10.1521/pedi.1999.13.1.18
65. Coid J, Ullrich S. Antisocial personality disorder is on a continuum with psychopathy. Compr Psychiatry. (2010) 51:426–33. doi: 10.1016/j.comppsych.2009.09.006
67. Woods L, Craster L, Forrester A. Mental Health Act transfers from prison to psychiatric hospital over a six-year period in a region of England. J Crim Psychol. (2020) 10:219–31. doi: 10.1108/JCP-03-2020-0013
68. Durcan G, Saunders A, Gadsby B, Hazard A. The Bradley Report Five Years On. London: Centre for Mental Health (2014).
69. Carroll A, Ellis A, Aboud A, Scott R, Pillai K. No involuntary treatment of mental illness in Australian and New Zealand prisons. J Forens Psychiatry Psychol. (2021) 32:1–28. doi: 10.1080/14789949.2020.1817524
70. Bone TA, Roberts M. An investigation into the routes to inpatient care at the Pantang Hospital in Ghana via the criminal justice system. Ghana Med J. (2019) 53:100–8. doi: 10.4314/gmj.v53i2.4
71. Till A, Forrester A, Exworthy T. The development of equivalence as a mechanism to improve prison healthcare. J R Soc Med. (2014) 107:179–82. doi: 10.1177/0141076814523949
72. Kooij J, Francken M. Diagnostic interview for ADHD in adults 2.0 (DIVA 2.0). In: Adult ADHD Diagnostic Assessment and Treatment. Hague: Diva Foundation (2010).
73. Mohr-Jensen C, Steinhausen H-C. A meta-analysis and systematic review of the risks associated with childhood attention-deficit hyperactivity disorder on long-term outcome of arrests, convictions, and incarcerations. Clin Psychol Rev. (2016) 48:32–42. doi: 10.1016/j.cpr.2016.05.002
74. Young S, Sedgwick O, Fridman M, Gudjonsson G, Hodgkins P, Lantigua M, et al. Co-morbid psychiatric disorders among incarcerated ADHD populations: a meta-analysis. Psychol Med. (2015) 45:2499–510. doi: 10.1017/S0033291715000598
75. Young S, Cocallis K. ADHD and offending. J Neural Transm. (2021) 128:1009–19. doi: 10.1007/s00702-021-02308-0
76. Grieger L, Hosser D. Attention deficit hyperactivity disorder does not predict criminal recidivism in young adult offenders: results from a prospective study. Int J Law Psychiatry. (2012) 35:27–34. doi: 10.1016/j.ijlp.2011.11.005
77. Gudjonsson GH, Sigurdsson JF, Sigfusdottir ID, Young S. A national epidemiological study of offending and its relationship with ADHD symptoms and associated risk factors. J Atten Disord. (2014) 18:3–13. doi: 10.1177/1087054712437584
78. Mannuzza S, Klein RG, Moulton III JL. Lifetime criminality among boys with attention deficit hyperactivity disorder: a prospective follow-up study into adulthood using official arrest records. Psychiatry Res. (2008) 160:237–46. doi: 10.1016/j.psychres.2007.11.003
79. Mordre M, Groholt B, Kjelsberg E, Sandstad B, Myhre AM. The impact of ADHD and conduct disorder in childhood on adult delinquency: a 30 years follow-up study using official crime records. BMC Psychiatry. (2011) 11:1–10. doi: 10.1186/1471-244X-11-57
80. Gunter TD, Arndt S, Riggins-Caspers K, Wenman G, Cadoret RJ. Adult outcomes of attention deficit hyperactivity disorder and conduct disorder: are the risks independent or additive? Ann Clin Psychiatry. (2006) 18:233–7. doi: 10.1080/10401230600948415
81. Sibley MH, Pelham WE, Molina BS, Gnagy EM, Waschbusch DA, Biswas A, et al. The delinquency outcomes of boys with ADHD with and without comorbidity. J Abnorm Child Psychol. (2011) 39:21–32. doi: 10.1007/s10802-010-9443-9
82. Kolla NJ, van der Maas M, Erickson PG, Mann RE, Seeley J, Vingilis E. Attention deficit hyperactivity disorder and arrest history: differential association of clinical characteristics by sex. Int J Law Psychiatry. (2018) 58:150–6. doi: 10.1016/j.ijlp.2018.04.006
83. Román-Ithier JC, González RA, Vélez-Pastrana MC, González-Tejera GM, Albizu-García CE. Attention deficit hyperactivity disorder symptoms, type of offending and recidivism in a prison population: the role of substance dependence. Crim Behav Mental Health. (2017) 27:443–56. doi: 10.1002/cbm.2009
84. Eme R, Young S. Reliability of ADHD in prison populations: a response to Murphy and Appelbaum. ADHD Rep. (2017) 25:1–6. doi: 10.1521/adhd.2017.25.5.1
86. Shaw P, Stringaris A, Nigg J, Leibenluft E. Emotion dysregulation in attention deficit hyperactivity disorder. Am J Psychiatry. (2014) 171:276–93. doi: 10.1176/appi.ajp.2013.13070966
87. American Psychiatric Association DSM. Diagnostic and Statistical Manual of Mental Disorders. DSM-5 (2013).
88. Falk Ö, Wallinius M, Lundström S, Frisell T, Anckarsäter H, Kerekes N. The 1% of the population accountable for 63% of all violent crime convictions. Soc Psychiatry Psychiatr Epidemiol. (2014) 49:559–71. doi: 10.1007/s00127-013-0783-y
89. Farrington DP, Ohlin LE, Wilson JQ. Understanding and Controlling Crime: Toward a New Research Strategy. Berlin: Springer Science & Business Media (2012).
90. Moffitt TE. Male antisocial behaviour in adolescence and beyond. Nat Hum Behav. (2018) 2:177. doi: 10.1038/s41562-018-0309-4
91. Retz W, Rösler M. The relation of ADHD and violent aggression: what can we learn from epidemiological and genetic studies? Int J Law Psychiatry. (2009) 32:235–43. doi: 10.1016/j.ijlp.2009.04.006
92. Gudjonsson GH, Wells J, Young S. Personality disorders and clinical syndromes in ADHD prisoners. J Atten Disord. (2012) 16:304–13. doi: 10.1177/1087054710385068
93. Mogavero F, Jager A, Glennon JC. Clock genes, ADHD and aggression. Neurosci Biobehav Rev. (2018) 91:51–68. doi: 10.1016/j.neubiorev.2016.11.002
94. Patel BD, Barzman DH. Pharmacology and pharmacogenetics of pediatric ADHD with associated aggression: a review. Psychiatr Q. (2013) 84:407–15. doi: 10.1007/s11126-013-9253-7
95. Beauchaine TP, Zisner AR, Sauder CL. Trait impulsivity and the externalizing spectrum. Annu Rev Clin Psychol. (2017) 13:343–68. doi: 10.1146/annurev-clinpsy-021815-093253
96. Noordermeer SD, Luman M, Oosterlaan J. A systematic review and meta-analysis of neuroimaging in oppositional defiant disorder (ODD) and conduct disorder (CD) taking attention-deficit hyperactivity disorder (ADHD) into account. Neuropsychol Rev. (2016) 26:44–72. doi: 10.1007/s11065-015-9315-8
97. Wolraich ML, Chan E, Froehlich T, Lynch RL, Bax A, Redwine ST, et al. ADHD diagnosis and treatment guidelines: a historical perspective. Pediatrics. (2019) 144:e20191682. doi: 10.1542/peds.2019-1682
98. Cortese S, Adamo N, Del Giovane C, Mohr-Jensen C, Hayes AJ, Carucci S, et al. Comparative efficacy and tolerability of medications for attention-deficit hyperactivity disorder in children, adolescents, and adults: a systematic review and network meta-analysis. Lancet Psychiatry. (2018) 5:727–38. doi: 10.1016/S2215-0366(18)30269-4
99. Koesters M, Becker T, Kilian R, Fegert JM, Weinmann S. Limits of meta-analysis: methylphenidate in the treatment of adult attention-deficit hyperactivity disorder. J Psychopharmacol. (2009) 23:733–44. doi: 10.1177/0269881108092338
100. Boesen K, Saiz LC, Erviti J, Storebø OJ, Gluud C, Gøtzsche PC, et al. The Cochrane Collaboration withdraws a review on methylphenidate for adults with attention deficit hyperactivity disorder. BMJ Evid Based Med. (2017) 22:143–7. doi: 10.1136/ebmed-2017-110716
102. Romanos M, Reif A, Banaschewski T. Methylphenidate for attention-deficit/hyperactivity disorder. JAMA. (2016) 316:994–5. doi: 10.1001/jama.2016.10279
103. Castells X, Blanco-Silvente L, Cunill R. Amphetamines for attention deficit hyperactivity disorder (ADHD) in adults. Cochrane Database Syst Rev. (2018) 8:CD007813. doi: 10.1002/14651858.CD007813.pub3
104. Punja S, Shamseer L, Hartling L, Urichuk L, Vandermeer B, Nikles J, et al. Amphetamines for attention deficit hyperactivity disorder (ADHD) in children and adolescents. Cochrane Database Syst Rev. (2016) 2:CD009996. doi: 10.1002/14651858.CD009996.pub2
105. Storebø OJ, Ramstad E, Krogh HB, Nilausen TD, Skoog M, Holmskov M, et al. Methylphenidate for children and adolescents with attention deficit hyperactivity disorder (ADHD). Cochrane Database Syst Rev. (2015) 2015:CD009885. doi: 10.1002/14651858.CD009885.pub2
106. Cunill R, Castells X, Tobias A, Capellà D. Atomoxetine for attention deficit hyperactivity disorder in the adulthood: a meta-analysis and meta-regression. Pharmacoepidemiol Drug Saf. (2013) 22:961–9. doi: 10.1002/pds.3473
107. Epstein T, Patsopoulos NA, Weiser M. Immediate-release methylphenidate for attention deficit hyperactivity disorder (ADHD). Cochrane Database Syst Rev. (2014). CD005041. doi: 10.1002/14651858.CD005041.pub2
108. Chang Z, Lichtenstein P, Långström N, Larsson H, Fazel S. Association between prescription of major psychotropic medications and violent reoffending after prison release. JAMA. (2016) 316:1798–807. doi: 10.1001/jama.2016.15380
109. Hassan L, Senior J, Frisher M, Edge D, Shaw J. A comparison of psychotropic medication prescribing patterns in East of England prisons and the general population. J Psychopharmacol. (2014) 28:357–62. doi: 10.1177/0269881114523863
110. Ginsberg Y, Lindefors N. Methylphenidate treatment of adult male prison inmates with attention-deficit hyperactivity disorder: randomised double-blind placebo-controlled trial with open-label extension. Br J Psychiatry. (2012) 200:68–73. doi: 10.1192/bjp.bp.111.092940
111. Konstenius M, Jayaram-Lindström N, Guterstam J, Beck O, Philips B, Franck J. Methylphenidate for attention deficit hyperactivity disorder and drug relapse in criminal offenders with substance dependence: a 24-week randomized placebo-controlled trial. Addiction. (2014) 109:440–9. doi: 10.1111/add.12369
112. Lichtenstein P, Halldner L, Zetterqvist J, Sjölander A, Serlachius E, Fazel S, et al. Medication for attention deficit–hyperactivity disorder and criminality. N Engl J Med. (2012) 367:2006–14. doi: 10.1056/NEJMoa1203241
113. Asherson P, Johansson L, Holland R, Fahy T, Forester A, Howitt S, et al. Randomised controlled trial of the short-term effects of OROS-methylphenidate on ADHD symptoms and behavioural outcomes in young male prisoners with attention-deficit/hyperactivity disorder (CIAO-II). Trials. (2019) 20:1–21. doi: 10.1186/s13063-019-3705-9
114. British National Formulary BNF. Methylphenidate hydrochloride. In: National Institute for Clinical Excellence, editor. British National Formulary. London: Joint Formulary Committee (2021). Available online at: https://bnf.nice.org.uk/drug/methylphenidate-hydrochloride.html
115. Bradshaw R, Pordes BAJ, Trippier H, Kosky N, Pilling S, O'Brien F. The health of prisoners: summary of NICE guidance. BMJ. (2017) 356:j1378. doi: 10.1136/bmj.j1378
116. Fazel S, Baillargeon J. The health of prisoners. Lancet. (2011) 377:956–65. doi: 10.1016/S0140-6736(10)61053-7
117. Sharma A, Couture J. A review of the pathophysiology, etiology, and treatment of attention-deficit hyperactivity disorder (ADHD). Ann Pharmacother. (2014) 48:209–25. doi: 10.1177/1060028013510699
118. Wilens TE, Morrison NR, Prince J. An update on the pharmacotherapy of attention-deficit/hyperactivity disorder in adults. Expert Rev Neurother. (2011) 11:1443–65. doi: 10.1586/ern.11.137
119. Moazen B, Saeedi Moghaddam S, Silbernagl MA, Lotfizadeh M, Bosworth RJ, Alammehrjerdi Z, et al. Prevalence of drug injection, sexual activity, tattooing, and piercing among prison inmates. Epidemiol Rev. (2018) 40:58–69. doi: 10.1093/epirev/mxy002
120. European Monitoring Centre for Drugs and Drug Addiction. Prisons and Drugs in Europe: The Problem and Responses. Lisbon: European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) (2012).
121. Wakeling H, Kieran L. Exploring Substance Use in Prisons: A Case Study Approach in Five Closed Male English Prisons. Ministry of Justice Analytical Series (2020).
122. Kalk NJ, Boyd A, Strang J, Finch E. Spice and all things nasty: the challenge of synthetic cannabinoids. Br Med J. (2016) 355:i5639. doi: 10.1136/bmj.i5639
123. Cleary L, Buber R, Docherty JR. Effects of amphetamine derivatives and cathinone on noradrenaline-evoked contractions of rat right ventricle. Eur J Pharmacol. (2002) 451:303–8. doi: 10.1016/S0014-2999(02)02305-1
124. Spiller HA, Hays HL, Aleguas A. Overdose of drugs for attention-deficit hyperactivity disorder: clinical presentation, mechanisms of toxicity, and management. CNS Drugs. (2013) 27:531–43. doi: 10.1007/s40263-013-0084-8
125. Barkla XM, McArdle PA, Newbury-Birch D. Are there any potentially dangerous pharmacological effects of combining ADHD medication with alcohol and drugs of abuse? A systematic review of the literature. BMC Psychiatry. (2015) 15:1–5. doi: 10.1186/s12888-015-0657-9
126. Hysek CM, Simmler LD, Schillinger N, Meyer N, Schmid Y, Donzelli M, et al. Pharmacokinetic and pharmacodynamic effects of methylphenidate and MDMA administered alone or in combination. Int J Neuropsychopharmacol. (2014) 17:371–81. doi: 10.1017/S1461145713001132
127. Cunill R, Castells X, Tobias A, Capellà D. Pharmacological treatment of attention deficit hyperactivity disorder with co-morbid drug dependence. J Psychopharmacol. (2015) 29:15–23. doi: 10.1177/0269881114544777
128. Faraone SV, Rostain AL, Montano CB, Mason O, Antshel KM, Newcorn JH. Systematic review: nonmedical use of prescription stimulants: risk factors, outcomes, and risk reduction strategies. J Am Acad Child Adolesc Psychiatry. (2020) 59:100–12. doi: 10.1016/j.jaac.2019.06.012
129. Bulger G. Safer Prescribing in Prisons, Guidance for Clinicians. London: Royal College of General Practitioners (2019).
130. Hulme S, Bright D, Nielsen S. The source and diversion of pharmaceutical drugs for non-medical use: a systematic review and meta-analysis. Drug Alcohol Depend. (2018) 186:242–56. doi: 10.1016/j.drugalcdep.2018.02.010
Keywords: ADHD, prison psychiatry, impulsivity, aggression, comorbidities
Citation: Tully J (2022) Management of ADHD in Prisoners—Evidence Gaps and Reasons for Caution. Front. Psychiatry 13:771525. doi: 10.3389/fpsyt.2022.771525
Received: 06 September 2021; Accepted: 04 February 2022;
Published: 18 March 2022.
Edited by:
J. Steven Lamberti, University of Rochester, United StatesReviewed by:
Deniz Cerci, University Hospital Rostock, GermanySamuele Cortese, University of Southampton, United Kingdom
Copyright © 2022 Tully. 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: John Tully, john.tully@nottingham.ac.uk