Aims/hypothesis An earlier meta-analysis showed that diabetes is a risk factor for the development and/or recurrence of depression. Yet whether this risk is different for studies using questionnaires than for those relying on diagnostic criteria for depression has not been examined. This study examined the association of diabetes and the onset of depression by reviewing the literature and conducting a meta-analysis of longitudinal studies on this topic. Methods EMBASE, MEDLINE and PsycInfo were searched for articles published up to September 2009. All studies that examined the relationship between type 2 diabetes and the onset of depression were included. Pooled relative risks were calculated using fixed and random effects models. Results Eleven studies met our inclusion criteria for this meta-analysis. Based on the pooled data, including 48,808 cases of type 2 diabetes without depression at baseline, the pooled relative risk was 1.24 (95% CI 1.09–1.40) for the random effects model. This risk was significantly higher for studies relying on diagnostic criteria of depression than for studies using questionnaires. However, this difference was no longer significant when controlled for year of publication. Conclusions/interpretation Compared with non-diabetic controls, people with type 2 diabetes have a 24% increased risk of developing depression. The mechanisms underlying this relationship are still unclear and warrant further research.

OBJECTIVE: Meta-analyses have shown that the risk for depression is elevated in type 2 diabetes. Whether this risk in individuals with impaired glucose metabolism (IGM) or undiagnosed diabetes (UDD) is elevated relative to normal glucose metabolism (NGM) or decreased relative to previously diagnosed type 2 diabetes (PDD) has not been the subject of a systematic review/meta-analysis. This study examined the prevalence of depression in IGM and UDD subjects relative to each other and to NGM and PDD subjects by reviewing the literature and conducting a meta-analysis of studies on this topic.RESEARCH DESIGN AND METHODS: EMBASE and MEDLINE databases were searched for articles published up to May 2010. All studies that compared the prevalence of depression in subjects with IGM and UDD were included. Odds ratios (ORs) were calculated using fixed and random-effects models.RESULTS: The meta-analysis showed that the risk for depression was not increased in IGM versus NGM subjects (OR 0.96, 95% CI 0.85–1.08). Risk for depression did not differ between individuals with UDD and individuals with either NGM (OR 0.94, 95% CI 0.71–1.25) or IGM (OR 1.16, 95% CI 0.88–1.54). Finally, individuals with IGM or UDD both had a significantly lower risk of depression than individuals with PDD (OR 0.59, 95% CI 0.48–0.73, and OR 0.57, 95% CI 0.45–0.74, respectively).CONCLUSIONS: Results of this meta-analysis show that the risk of depression is similar for NGM, IGM, and UDD subjects. PDD subjects have an increased risk of depression relative to IGM and UDD subjects.

Evidence suggests that stressful experiences might affect diabetes, in terms of both its onset and its exacerbation. In this article, the authors review some of this evidence and consider ways in which stress might affect diabetes, both through physiological mechanisms and via behavior. They also discuss the implications of this for clinical practice and care.

Aims: To assess the prevalence and management of depressive disorders in people with Type 2 diabetes in different countries.Methods: People with diabetes aged 18–65 years and treated in outpatient settings were recruited in 14 countries and underwent a psychiatric interview. Participants completed the Patient Health Questionnaire and the Problem Areas in Diabetes scale. Demographic and medical record data were collected.Results: A total of 2783 people with Type 2 diabetes (45.3% men, mean duration of diabetes 8.8 years) participated. Overall, 10.6% were diagnosed with current major depressive disorder and 17.0% reported moderate to severe levels of depressive symptomatology (Patient Health Questionnaire scores >9). Multivariable analyses showed that, after controlling for country, current major depressive disorder was significantly associated with gender (women) (P<0.0001), a lower level of education (P<0.05), doing less exercise (P<0.01), higher levels of diabetes distress (P<0.0001) and a previous diagnosis of major depressive disorder (P<0.0001). The proportion of those with either current major depressive disorder or moderate to severe levels of depressive symptomatology who had a diagnosis or any treatment for their depression recorded in their medical records was extremely low and non‐existent in many countries (0–29.6%).Conclusions: Our international study, the largest of this type ever undertaken, shows that people with diabetes frequently have depressive disorders and also significant levels of depressive symptoms. Our findings indicate that the identification and appropriate care for psychological and psychiatric problems is not the norm and suggest a lack of the comprehensive approach to diabetes management that is needed to improve clinical outcomes.