Lifetime depression history and depression risk in type 2 diabetes: A case-control study

To assess whether a personal history of depression assists in risk prediction for depression in type 2 diabetes.

Age- and sex-matched participants with and without diabetes from the Busselton Health Survey were assessed for current and previous depression using the 9-item Patient Health Questionnaire and the Brief Lifetime Depression Scale (BLDS). In the diabetic participants, the temporal relationship between first depression episode and diabetes onset was also explored.

In 184 paired participants (age 70.2±10.1years, 50% female), those with diabetes had a higher prevalence of any current depression (12.5% vs 4.3%, P<0.01) and lifetime history of major depression (30.6% vs 21.1%, P=0.06) compared to those without diabetes. After adjustment, lifetime major depression history was independently associated with any current depression in the combined sample (odds ratio (95% CI): 5.55 (3.09-9.98), P<0.001), in those with diabetes (4.17 (2.00-8.71), P<0.001), in those without diabetes (8.29 (3.24-21.23), P<0.001) and in diabetes whether sub-divided by depression first occurring before or after diabetes onset (before: 3.16 (1.38-7.24), P=0.007; after: 2.77 (1.00-7.70), P=0.051).

Obtaining a lifetime history of major depression using the BLDS assists in depression risk prediction in type 2 diabetes regardless of whether depression preceded diabetes onset or not.