​Summary: Serious Psychological Distress (SPD), an indicator of mental illness, is on the rise in California. From 2014 to 2018, the percentage of adults in California with SPD increased by 41.6%, from 7.7% to 10.9%.  Using 2014–2018 California Health Interview Survey (CHIS) data, this brief evaluates the impact of the social determinants of mental health inequities across a five-year period to understand the upward trend of SPD in California.

Findings: Upticks in SPD were largest among adults who were ages 18–24, male, employed part-time, Asian, and identifying as LGB. Persistently high percentages of SPD across all years were found among those ages 18–24, female, unemployed and looking for work, with less formal education, low income, publicly insured, and identifying as LGB. These findings support the need for equity-based policies, programs, and services that reduce inequities in education, employment, income, and health insurance coverage. Investment in supports and services for young adults, the LGBTQ community, and communities at risk for lower socioeconomic status are crucial.