# Prevalence of Mild to Moderate Mental Illness, Correlates of Treatment Patterns, and Perceived Unmet Need among U.S. Adults: Results from the National Survey on Drug Use and Health, 2021

**Authors:** Valerie L. Forman-Hoffman, Megan Flom, Andre Williams, Timothy Mariano

PMC · DOI: 10.2174/0117450179394114251013063017 · 2025-11-21

## TL;DR

About 1 in 6 U.S. adults had mild to moderate mental illness in 2021, but most did not receive treatment, highlighting a need for better access to affordable mental health care.

## Contribution

This is the first study to report nationally representative prevalence and correlates of mild to moderate mental illness among U.S. adults.

## Key findings

- Approximately 17.2% of U.S. adults had past-year mild to moderate mental illness.
- Over 62% of those receiving treatment used virtual services.
- Most individuals with mild to moderate mental illness did not receive treatment.

## Abstract

Mental health issues continue to affect millions despite the availability of evidence-based treatment. The burden of illness and associated characteristics of mild to moderate mental illness (MMMI) among community-dwelling U.S. adults has not been reported in the peer-reviewed literature to date.

Analyses of the cross-sectional 2021 National Survey on Drug Use and Health (NSDUH) conducted across the U.S. allowed for the estimation of the prevalence and correlates of MMMI as well as of the overall and virtual treatment landscape, perceived unmet need, and barriers to care.

Nearly 44 million community-dwelling U.S. adults (17.2%), about 1 in 6, are estimated to have past-year MMMI, of whom 41.3% report mental health treatment receipt. Over 62% of those who received mental health treatment did so virtually.

MMMI commonly affected U.S. adults; a majority are not getting treatment. Several correlates of MMMI and treatment receipt might point to demographic and clinical groups in need to additional services.

This study is the first of its kind to report nationally representative estimates and correlates of MMMI among community-dwelling U.S. adults. Despite the widespread use of virtual services when accessing mental health treatment, findings suggest the need for access to low-cost, easily accessible, on-demand mental health services to better serve adults with MMMI.

## Linked entities

- **Diseases:** mental illness (MONDO:0002025)

## Full-text entities

- **Diseases:** MMMI (MESH:C565640), Mental health (OMIM:603663), Mental Illness (MESH:D001523)

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Source: https://tomesphere.com/paper/PMC12895429