Clinically relevant depression in patients with type 1 and type 2 diabetes; a nationwide study (TEMD-2 depression)

PURPOSE: Depression is a common but underrecognized comorbidity in individuals with diabetes and is associated with adverse clinical outcomes. This nationwide study aimed to determine the prevalence of clinically relevant depression (CRD) among adults with type 1 and type 2 diabetes in Türkiye and to identify clinical and metabolic factors independently associated with CRD. METHODS: This cross-sectional analysis was conducted within the Turkish nationwide survEy of glycemic and other Metabolic parameters of patients with Diabetes mellitus-2 (TEMD-2), a multicenter study including adults followed in tertiary endocrinology centers across Türkiye. CRD was defined as a Patient Health Questionnaire-9 score ≥ 10 and/or current antidepressant use. RESULTS: A total of 5.266 patients were included. The prevalence of CRD was similar in type 1 and type 2 diabetes (29.4% vs. 27.6%, p = 0.345). In both diabetes types, CRD was significantly more common among women. Patients with CRD had higher body mass index, poorer glycemic control, higher rates of hypoglycemia, and lower achievement of metabolic targets. Microvascular and macrovascular complications were more frequent in patients with CRD. In multivariable analyses, female sex, smoking, and polypharmacy were independently associated with CRD in both diabetes types, while obesity, poor glycemic control, and vascular complications were additional independent associates in type 2 diabetes. CONCLUSION: CRD affects nearly one-third of adults with diabetes, regardless of diabetes type, and is associated with greater comorbidity burden and suboptimal metabolic control. These findings support routine depression screening as an integral component of comprehensive diabetes care. The study is registered at ClinicalTrials.gov (NCT06347445).