Point prevalence of common mental health conditions in Nigeria: a systematic review and meta-analysis

Abstract

Nigerian mental health prevalence data are dispersed across conditions, instruments, and high-risk settings, limiting their use for research planning. This review synthesized current and point prevalence for 10 mental health condition families in Nigerian populations. PubMed/MEDLINE and Europe PMC were the core bibliographic sources, supplemented by African Journals Online and Google Scholar. Searches ran on 6 August 2026. Eligible reports used validated current or ≤30-day measures. Joanna Briggs Institute prevalence criteria informed risk-of-bias judgements. Logit-transformed inverse-variance random-effects models with restricted maximum likelihood variance were fitted in R; screening and diagnostic estimates were analyzed separately. A total of 103 reports contributed 133 estimates. Pooled screening prevalence was 30.2% (95% confidence interval 24.6-36.5%) for depression and 34.8% (25.9-44.9%) for anxiety; diagnosed depression was 20.2% (15.4-26.0%). Current substance-use disorder prevalence was 16.4% (11.9-22.3%), diagnosed dementia 2.2% (0.7-6.9%), cognitive-impairment screening 24.1% (21.7-26.6%), psychosis 4.2% (1.3-12.7%), antenatal depression 16.7% (8.4-30.4%), postpartum screening 18.5% (9.0-34.4%), diagnosed post-traumatic stress disorder 12.2% (4.5-29.3%; trauma-exposed screening 58.8%, 37.1-77.5%), current suicidal ideation 20.4% (11.6-33.4%), current attempts 2.3% (0.7-6.9%), and attention-deficit/hyperactivity disorder 8.5% (5.3-13.4%). No eligible bipolar estimate was found. Heterogeneity was usually substantial (I2 58.0-99.3%). These are planning values for populations resembling the contributing studies, not national rates. Researchers should match p to the target population and measurement method; sparse, heterogeneous outcomes require conservative sensitivity calculations.