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Mental Illness and Substance Use Disorders in California

Overhead shot of hands holding tissues.
A qualitative study of people with dual diagnoses for the California Health Care Foundation
  • Client
    California Health Care Foundation
  • Dates

To better understand how Californians with both mental illness and substance use disorder attempt to and actually receive treatment, NORC at the University of Chicago conducted 93 in-depth interviews in 2020 with subject matter experts, provider-administrators, providers, and individuals who have both disorders. Our sample of 54 people with dual diagnoses represented the diversity of Californians to ensure we could see the intertwined factors that impact access to care, health outcomes, and health care experience. In one-on-one interviews, these individuals were able to describe, in their own words, both their obstacles to treatment and what is working well. 

Our research, conducted on behalf of the California Health Care Foundation and published in 2021, exposed pervasive problems in a health care system that continues to be divided in two—one for mental health treatment and one for substance use disorders, each with its own data and financing mechanisms, charting requirements, and privacy regulations. Physical health care is yet another separate system. 

The siloed care system is burdensome for patients and providers and directly contributes to poor health outcomes. The difficulties begin as soon as people enter treatment. They are typically given a primary diagnosis of mental illness or substance use disorder, but rarely both. The health system’s reliance on this either/or “primary diagnosis” determines where people enter care and how they self-identify moving forward, putting them at risk of relapse or never having their illnesses fully treated. 

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