Aims/hypothesis: Individuals with diabetes have increased mortality rates compared with the general population. In patients with type 2 diabetes depression further contributes to the increased mortality. Depression and mortality rates in patients with type 1 diabetes are an understudied phenomenon. We therefore studied their association in a prospective setting.
Methods: We followed 4,174 participants (51% men, age 39 ± 12 years, diabetes duration 22 ± 12 years [mean ± SD]) in the Finnish Diabetic Nephropathy Study (FinnDiane) for an average of 9 years. Depression was defined as purchase of antidepressant agents at baseline and during follow-up. These data were obtained from the Finnish Drug Prescription Register. Data on all-cause mortality and cause of death were obtained from the Finnish Cause of Death Register.
Results: At baseline, 313 (7.5%) patients had purchased antidepressant agents. During follow-up 758 (18.2%) additional cases were observed. Purchasers of antidepressant agents at baseline had the highest 10-year cumulative mortality rate (22.5% [95% CI 18.1, 26.6]), followed by those with such purchases during follow-up (18.0% [15.4, 20.5]) and those with no purchases (10.1% [9.0, 11.2], p < 0.001). In the adjusted Cox regression models (age, diabetes duration, diastolic blood pressure, smoking, HbA(1c) and nephropathy), the purchase of antidepressant agents at baseline was associated with mortality in women, but not in men. Cardiovascular diseases were the major cause of death in non-purchasers of antidepressant agents. In antidepressant purchasers, chronic diabetic complications were the most frequent underlying cause of death.
Conclusions/interpretation: In a population of patients with type 1 diabetes, purchase of antidepressant agents was associated with increased mortality rates in women, but not in men.