# Depression comorbidity in children and adolescents with type 2 diabetes mellitus: a systematic review and meta-analysis

## TL;DR

About one in four children and adolescents with type 2 diabetes also experience depression, with differences in diagnosis methods and blood sugar levels affecting reported rates.

## Contribution

This study provides the first meta-analysis estimating depression prevalence in youth with type 2 diabetes and identifies key factors contributing to variability in reported rates.

## Key findings

- The pooled prevalence of depression in youth with type 2 diabetes is 23.1%.
- Depression prevalence is higher in those with lower HbA1c levels and when using self-report scales.
- Standardized diagnostic procedures are needed to improve mental health outcomes in this population.

## Abstract

Depression is a frequent psychological comorbidity among youth with type 2 diabetes mellitus (T2DM), yet reported prevalence rates vary widely across studies. This meta-analysis aimed to estimate the pooled prevalence of depression and explore sources of heterogeneity.

This meta-analysis is registered with PROSPERO (CRD420251126166). We systematically searched PubMed, Embase, Web of Science, Cochrane Library, CINAHL, and PsycINFO from inception to October 24, 2025. The pooled prevalence was calculated using a random-effects model. Subgroup analyses and meta-regression were conducted to investigate potential sources of heterogeneity. All processes of study screening, data extraction, and quality assessment were carried out independently by two researchers.

Seventeen studies comprising 5,215 participants were included. The pooled prevalence of comorbid depression was 23.1% (95% CI: 18.0%–29.1%), with substantial heterogeneity (I² = 93%). Subgroup analyses indicated that prevalence differed significantly by HbA1c level and assessment method. Participants with HbA1c < 7% showed higher prevalence (52.0%) than those with HbA1c ≥ 7% (24.0%). Studies using self-report scales reported higher prevalence (25.2%) than those using clinical diagnostic criteria (12.2%). Univariate meta-regression indicated that both HbA1c level and the depression assessment method significantly influenced the reported prevalence of depression.

Approximately one in four youth with T2DM experience depression. Variations in assessment method and glycemic control may contribute to the heterogeneity of reported prevalence. These findings underscore the importance of standardized diagnostic procedures and early psychological screening in pediatric T2DM populations to improve both mental health and diabetes outcomes.

https://www.crd.york.ac.uk/prospero/, identifier CRD420251126166