New research shows that depression and impulse control disorders (eating disorders in particular) are independently associated with diabetes diagnosis, after adjustment for presence of other mental disorders. The research, published in Diabetologia (the journal of The European Association for the Study of Diabetes), supports the focus on depression as an independent risk factor for diabetes, but also suggests this focus should be extended to impulse control disorders. The study is the first to report on the association between impulse control disorders and diabetes diagnosis. The research is by Dr Peter de Jonge, Interdisciplinary Center for Psychopathology and Emotion Regulation, University Medical Center Groningen, University of Groningen, Netherlands, and colleagues worldwide.

While previous studies have explored the associations between diabetes and depression, they have limitations. First, most have been conducted in Europe and the USA, and diabetes and depression vary in prevalence worldwide, thus more global studies are needed. Secondly, and the authors say more importantly, depression often co-occurs with several other mental health disorders - not only with anxiety disorders but also with many of the other Diagnostic Statistical Manual, 4th edition (DSM-IV) mental disorders such as eating disorders and alcohol abuse. Thus the authors did this new study, within the framework of the World Mental Health Surveys* to examine the associations between a wide range of DSM-IV mental disorders and diabetes diagnosis. This approach enabled them to investigate the association between first onset of mood, anxiety, impulse control (including eating disorders) and substance use disorders with diabetes diagnosis in a large international sample, with data coming from 19 countries: Colombia, Mexico, Peru, USA, Shenzhen (China), Japan, New Zealand, Belgium, France, Germany, Italy, the Netherlands, Romania, Spain, Portugal, Israel, Iraq, the UK (Northern Ireland) and Poland. More than 50,000 participants were included in the analysis.

The authors identified 2,580 cases of adult-onset diabetes (diagnosed in those aged 21 years and over). Although all 16 DSM-IV disorders were associated with diabetes diagnosis, the same was not true after adjustment for the presence of other mental health conditions. After this adjustment, only depression (30% increased risk), intermittent explosive disorder (60% increased risk), binge eating disorder (2.6 times increased risk) and bulimia nervosa (2.1 times increased risk) independently increased the risk of diabetes diagnosis. While the association between depression and diabetes is within the range reported in other meta-analyses, the authors say the association between impulse control disorders (including eating disorders) and diabetes has not been reported before.

While the population-level estimates** of prevalence for these mental health disorders vary (0.9% for binge eating disorder, 0.5% for bulimia nervosa and 1.8% for intermittent explosive disorder and 11.3% for depression), at a population level effective interventions to prevent these conditions might ultimately, suggest the authors, prevent substantial numbers of diabetes diagnoses.

The authors conclude: "Our findings thus suggest that the focus on depression in the context of diabetes prediction is warranted, but this focus may be extended to impulse control disorders."