Prevalence of unmet need for mental health care and barriers to treatment among US adults: a systematic review and meta-analysis of nationally representative surveys

Retrospective registration of a systematic review and meta-analysis of cross-sectional studies based on nationally representative US household surveys (e.g., NSDUH, NHIS, MEPS, NCS-R). The review estimates the 12-month prevalence of perceived unmet need for mental health care among adults overall and among adults with mental illness, the prevalence of self-reported barriers to treatment (cost, not knowing where to go, stigma or confidentiality, believing one could handle the problem alone), and the association between insurance status and unmet need. Searches (PubMed/MEDLINE, Europe PMC, OpenAlex, citation searching) were run in October–November 2026. This registration was made after data extraction and analysis; deviations from the original protocol are listed below.