Associations of diabetes severity and risk of depression: a population-based cohort study

Previous literature investigating effects of diabetes complications on subsequent depression have been inconsistent. We aim to investigate associations of diabetes, complication severity, and depression.

This study used a nationwide database to establish an 11-year cohort comprised of people with new onset Type II diabetes mellitus (DM) aged 20 and above.

Severity of DM was measured using the adapted Diabetes Complication Severity Index (aDCSI). Status of depression was determined by having one recorded depression diagnosis from the inpatient setting or three recorded depression diagnoses from the outpatient setting. The risk of depression was analyzed by multivariate Cox proportional models.

In 50,590 cases with new onset DM from years 2000 to 2011, the incidence of depression increased with severity and rates of progressions in diabetes complications regardless of demographic status, comorbidities, or medication compliance. Adjusted hazard ratios (aHR) of depression were 1.21, 1.25, 1.48 (p<0.001 for trend) in patients with a total aDCSI score of 1, 2, and > 3, respectively. Risks of depression were the highest in subgroup with the most serious progression (change of aDCSI score >2 per year) (aHR ranged between 11.6~26.0). Elevated risks of depression (aHR: 1.59~4.36) were also observed in the slower progression subgroups throughout the disease course.

Risks of depression were associated with multiple DM-related complications and rates of progression in severity.