Treatment Patterns and Barriers to Care Among U.S. Adults With Co-Occurring Substance Use Disorder and Mental Illness

This study aimed to examine treatment patterns among U.S. adults with co-occurring substance use disorder (SUD) and mental illness, identify sociodemographic factors associated with receipt of treatment for both conditions, and characterize barriers to care.

The authors analyzed cross-sectional data from the 2021-2023 National Survey on Drug Use and Health. Adults age 18 years and older who met criteria for past-year SUD and either any mental illness or serious mental illness were included. The primary outcome was receipt of treatment for both conditions in the past year, and secondary outcomes included self-reported barriers to treatment. Weighted prevalence estimates and multivariable logistic regression models were used.

Among adults with co-occurring SUD and any mental illness, receipt of treatment for both increased from 7.5% in 2021 to 16.9% in 2022 and 18.2% in 2023. Among adults with co-occurring SUD and serious mental illness, receipt of treatment for both increased from 12.3% in 2021 to 25.0% in 2022 and 25.6% in 2023. Female sex, older age, and poorer self-rated health were associated with higher odds of receiving treatment for both conditions. Non-White and uninsured adults had significantly lower odds. Less than 2% of untreated adults reported perceiving a need for and seeking treatment. Commonly reported barriers included treatment not being a priority, stigma, cost, limited access, and lack of readiness.

Receipt of both substance use treatment and mental health treatment remained low among U.S. adults with co-occurring disorders despite modest post-COVID-19 pandemic increases. Persistent disparities and barriers suggest a need for stronger parity enforcement, stable financing, and improved coordination across behavioral health services.