Current data shows that more than 3.6 million adults in the U.S. had co-occurring serious mental illness (SMI) and a substance use disorder (SUD) in the past year. Here is a breakdown of this data into specific age groups:
Adults who have SMI show higher rates of SUD than people who do not experience mental illness. For example, nearly half of adults with SMI (49.4 percent) report illicit drug use in the past year. Yet only 16.6 percent of adults with no mental illness report illicit drug use in the past year.
Substance Abuse and Mental Health Services Administration. (2020). Key substance use and mental health indicators in the United States: Results from the 2019 National Survey on Drug Use and Health (HHS Publication No. PEP20-07-01-001, NSDUH Series H-55). Rockville, MD: Center for Behavioral Health Statistics and Quality, Substance Abuse and Mental Health Services Administration.