5.6% Of Adults Had Serious Mental Illness In 2024; Prevalence Is Highest Among Those Ages 18 To 25, At 9.4%

About 5.6% of adults in the United States aged 18 and older had serious mental illness (SMI) in 2024, according to a recent national survey. The prevalence of SMI varied by age group, from 9.4% among those aged 18 to 25, to 7.5% among those aged 26 to 49, to 2.8% among those age 50 and older. SMI;refers to the presence of a diagnosed or diagnosable mental, behavioral, or emotional disorder that substantially interferes with or limits one or more major life activities.;

Key findings include:

The prevalence of SMI has remained steady . . .