Prevalence, Severity and Determinants of Depression in Patients with Type 2 Diabetes Mellitus

Introduction: Patients with Type 2 Diabetes Mellitus (T2DM) are at higher risk to develop depression. Depression in turn adversely affects glycaemic control and increases the risk of diabetes-related complications and mortality. There is a large variation among Indian studies on prevalence of depression in T2DM and associated risk factors. Aim: To assess the prevalence, severity, and determinants of depression among patients with T2DM. Materials and Methods: The study was conducted at a Tertiary Care Hospital during February 2018-February 2019, in North-Indian state of Uttarakhand. Study subjects were patients with T2DM, age >18 years. Based on exclusion and inclusion criterias, a total sample of 290 patients were studied. Presence of depression was assessed using Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria. Hamilton Depression Rating Scale (HAM-D) was used to estimate the severity of depression. Unpaired t-test and Mann-Whitney U test were used to compare continuous variables between subjects with and without depression. Chi-Square test was used to analyse categorical data. Binary logistic regression analysis was used to study the association between likelihood of depression and predictor variables. Results: Among 290 (155 males and 135 females, mean age of all subjects 58.2 +/- 11.08 years) study subjects with T2DM, 64 (22.1%) were found to have depression using DSM-5 criteria. Out of these 64 patients with depression, 46 were detected to have mild depression, 14 moderate depression and 4 severe depression using HAM-D scale. Subjects with T2DM and depression had: higher proportion of females (62.5% vs. 42.0%; p-value 0.004); lower literacy level (53.1% vs. 67.3%; p-value 0.037); higher frequency of diabetic retinopathy (85.9% vs. 62.8%; p-value <0.001) and diabetic kidney disease (43.8% vs. 27.4%; p-value 0.013); higher Fasting Plasma Glucose (FPG) (217.7 +/- 94.62 vs. 190.0 +/- 76.45 mg/dL; p-value 0.040); and lower haemoglobin (10.8 +/- 2.49 vs. 11.7 +/- 2.37 gm/dL; p-value 0.010) compared to the subjects without depression. On binary logistic regression analysis, female gender (OR 2.457, 95% CI 1.368-4.413, p-value 0.003) and diabetic retinopathy (OR 3.842, 95% CI 1.7888.255, p-value 0.001) remained significantly associated with likelihood of depression. Conclusion: Depression was present in one-fifth of the study subjects with T2DM. Majority of them had mild depression. Female gender and diabetic retinopathy were associated with increased likelihood of depression.