Prevalence of diagnosed depression in South Asian and white European people with type 1 and type 2 diabetes mellitus in a UK secondary care population

Aim: To examine the prevalence and correlates of diagnosed depression among South Asians and white Europeans with type 1 and type 2 diabetes mellitus, attending a specialist diabetes clinic in the UK. Study design and methods: A cross-sectional study was conducted using the hospital clinic's computerised database. Medical and demographic data were extracted for 6230 people with diabetes attending the clinic between 2003 and 2005. Multiple logistic regression was used to model ethnic differences in the probability of diagnosed depression after controlling for demographic and diabetes related factors. Analyses were conducted separately for type 1 and type 2 diabetes. Results: The unadjusted prevalence of depression in people with type 1 and type 2 diabetes was 8.0% and 9.3%, respectively. Risk factors for depression in type 1 diabetes included female gender, diabetes related complications, and comorbidities. In people with type 2 diabetes the risk factors for depression included younger age, diabetes related complications, comorbidities, insulin use and deprivation. In addition, white Europeans were significantly more likely to be diagnosed with depression compared to South Asians (odds ratio (OR) 1.59, 95% confidence interval (CI) 1.21 to 2.08; p < 0.001). Further interaction analyses revealed no evidence that the association between ethnicity and depression differed according to any of the other factors examined in this study. Conclusions: The findings add to the limited body of knowledge regarding ethnic differences in depression and diabetes. Among those with type 2 diabetes, white Europeans had nearly 60% higher adjusted odds of diagnosed depression compared to South Asians. Disparities may be due to differences in presentation or identification of depression between these two ethnic groups.