The Body and Mind: the Impact of Obesity in Severe Mental Illness.

For people experiencing severe mental illness, obesity can prove both life-restricting and life-shortening. With a prevalence double that of people without mental illness, obesity contributes to elevated rates of cardiovascular disease and diabetes that underpin a potentially preventable and tragic 20 year abbreviation in life expectancy. Nor is premature death the only concern. Strongly linked to prescribed antipsychotic medication, extreme weight gain can further increase the stigma of mental illness, reinforcing poor self-esteem and negative views of treatment that can create a harmful spiral of antipsychotic discontinuation and relapsing mental illness. However, little is understood about the mechanisms by which psychotropic medications promote weight gain and obesity, nor the optimal approaches to prevent or treat obesity in people with severe mental illness. Early evidence indicates that antipsychotic medications interrupt central feeding/satiety pathways to promote hunger and food overconsumption, however, much remains to be clarified, to guide therapeutic strategies and provide therapeutic targets. In addition to an effect of antipsychotic treatment, it is clear that other psychotropic medications also promote weight gain. Mechanisms leading to antipsychotic-induced weight gain do not explain the weight promoting effects observed for many antidepressant medications and their associated risks of diabetes, hypertension, dyslipidaemia and other metabolic abnormalities. Although psychiatric medication plays an important role in weight gain, it is important to appreciate that other lifestyle and illness factors contribute to weight gain in people with severe mental illness. The clinical breadth of obesity and metabolic disturbances in people with severe mental illness has not been extensively re-evaluated for some years, with data gaps on the impact of obesity or rapid weight gain on polycystic ovary syndrome, pre-diabetes and its progression to diabetes, obstructive sleep apnoea, other disorders of circadian rhythms, non-alcoholic fatty liver disease and cirrhosis and cancer. Finally, much remains to clarified as to the optimal clinical strategies to address obesity, or prevent it, or prevent and treat obesity-related co-morbidities in this vulnerable population who suffer reduced access to health care and disparities in service provision (if not over discrimination) when they do present to clinical facilities.

This aims of this Research Topic are to invite novel evidence from basic and clinical studies of psychotropic medications and epidemiology that documents the burden of endocrine, metabolic and other obesity-associated conditions in people with severe mental illness, interventions to treat or prevent obesity in severe mental illness, and reviews and expert opinion in this area. Our broader aim is to promote greater understanding of obesity in severe mental illness, for best practice and to inform, guide and promote further basic and clinical research in this area.