According to a 2021 report by the Substance Abuse and Mental Health Services Administration (SAMHSA), the states with the highest rates of mental illness in the past 12 months are:
Utah (29.68%)
Vermont (27.46%)
West Virginia (27.10%)
Oregon (26.86%)
Alaska (26.73%)
The report also found that the states with the lowest rates of mental illness were:
New Jersey (11.38%)
Wisconsin (11.56%)
Massachusetts (11.94%)
Connecticut (12.04%)
New York (12.10%)
The report notes that these estimates are based on data from the National Survey on Drug Use and Health (NSDUH), which is a large, annual survey of Americans aged 18 and older. The NSDUH asks respondents about a variety of mental health conditions, including major depression, anxiety disorders, and substance use disorders.