Depression and Its Association With Microvascular and Macrovascular Complications in Type 2 Diabetes

BACKGROUND: Type 2 diabetes mellitus (T2DM) and depression frequently co-occur, but the specific clinical factors driving this association remain incompletely understood, particularly in Middle Eastern populations. OBJECTIVE: This study is aimed at investigating the association between T2DM and depression and identifying which clinical factors (complications, glycemic control, and treatment modality) are most strongly associated with depression risk in a Syrian patient cohort. METHODS: A case-control study enrolled 225 patients with T2DM and 226 nondiabetic controls. Depression was assessed using the Hamilton Depression Rating Scale (HDRS) and the Depression, Anxiety, and Stress Scales (DASS-21). Associations were analyzed using chi-square tests and binary logistic regression, with adjustment for age and sex in subgroup analyses. RESULTS: Depression prevalence was significantly higher in the T2DM group (68.4% by HDRS and 68.9% by DASS-21) than in controls (40.3% and 41.6%, respectively). A T2DM diagnosis was associated with approximately threefold increased odds of depression (OR = 3.22, 95% CI [2.19-4.74] for HDRS; OR = 3.12, 95% CI [2.11-4.58] for DASS-21). Microvascular complications were associated with a marked increase in depression odds (OR = 17.05 - 17.89). Achieving glycemic control was strongly protective (OR = 0.116 - 0.125). Complex insulin-based regimens were associated with greater depression severity, even when the binary presence of depression did not differ significantly by treatment type. CONCLUSION: In this Syrian cohort, T2DM was associated with a threefold higher odds of depression, but this risk was not uniform. The presence of microvascular complications was the strongest associated factor. These findings support the implementation of routine depression screening in diabetes care, particularly for patients with complications or complex treatment regimens, and highlight that intensive diabetes management may also contribute to depression prevention.