A Systematic Review and Meta-Analysis to Examine the Prevalence of Co-Morbid Depression in People with Type 1 and Type 2 Diabetes

Abstract

Background: Current research suggests that people with diabetes are more likely to suffer with depression. However, inconsistencies have been reported in the prevalence of depression in diabetes, with previous systematic reviews including studies with small numbers of participants, or without adequate control subjects. This is the first systematic review to estimate the prevalence and odds of depression in people with Type 1 and Type 2 diabetes, compared to those without diabetes, and estimate prevalence rates by different methods used to assess depression or depressive symptoms. Methods: According to PRISMA guidelines we searched MEDLINE, EMBASE and PSYCHINFO, from 1 January 1985 to 1 October 2020. Studies were excluded if they failed to have an adequate control group, specified type of diabetes, or reported depression prevalence by type of diabetes. Findings: 33 studies were selected for inclusion; 2 for Type 1 diabetes, 28 for Type 2 diabetes, and 3 for both Type 1 and Type 2 diabetes. The prevalence of diagnosed depression or elevated depressive symptoms was significantly higher in people with Type 1 (16% vs 12%, OR = 1.91 (1.46,2.50), or Type 2 diabetes (18% vs 11%, OR = 1.64 (1.45,1.86) compared to those without diabetes. There was no association between study effect size and mean age or gender. The prevalence of depression was significantly higher in people with diabetes, compared to those without diabetes, when depression was self-reported compared to doctor diagnosed (25% vs 7%, self-reported depression OR=1.87 (1.59,2.19) and doctor diagnosed OR=1.22 (1.07, 1.38); p =0.021). Prevalence and odds of depression or elevated depressive symptoms in people with diabetes, compared to without, differed significantly between studies set in specialist care, compared to community or primary care (36% vs 13%, specialist care OR = 2.71 (1.87,3.92) and community or primary care OR= 1.56 (1.38,1.76); p =0.003). There was no significant change in the reported prevalence of depression in individuals with diabetes, over a period of 30 years (1988-2018). Interpretation: Depression prevalence has not changed over the last 30 years, despite improvements in treatments and self-management education programmes. Effective chronic disease management in people with diabetes is important, particularly screening and managing depression and diabetes distress in specialist care settings. Funding Statement: None. Declaration of Interests: The authors declare no competing interests.