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New Research Sheds Light on Prevalence of Serious Mental Illness Among Unsheltered L.A. Residents Enrolled in Street Outreach Services

Los Angeles, CA—May 24, 2022: A new analysis by the nonpartisan California Policy Lab (CPL) uses data from L.A.’s Street Outreach programs to shed light on the mental health and housing outcomes of more than 45,000 L.A. residents who were unsheltered and received Street Outreach services between July 1, 2019 and June 30, 2020.

The analysis links enrollment data from the Street Outreach program to data from the LA County Department of Mental Health and the LA County Department of Health Services to provide estimates of the prevalence of psychotic spectrum disorders (“PSD”) and other serious mental illness (“SMI”) among people who receive Street Outreach services. Unsheltered individuals with SMI may experience symptoms that could cause or contribute to losing housing and that could lengthen the duration of homelessness. This group may need intensive, specialized, and coordinated care in order to exit homelessness. The estimates are considered a lower bound because if somebody received a SMI diagnosis or treatment outside of DMH or DHS, it would not be included in this analysis. The new research also shows housing placements for people who were in Street Outreach programs and shows how housing placements vary based on demographic and SMI characteristics.

Key findings:
• The vast majority (83%) of Street Outreach participants do not have a County service history with a diagnosis for any serious mental illness in the five years before enrolling in Street Outreach services.
• 10% of Street Outreach participants (4,584 people) have been diagnosed with a psychotic spectrum disorder (PSD) within five years prior to their enrollment in Street Outreach.
• An additional 7% of participants (3,277) have been diagnosed for other serious mental illness within five years prior to their Street Outreach enrollment.
• Eighty percent of Street Outreach participants with PSD have previously received homelessness services, compared to 75% of people with Other SMI diagnoses. Only 31% of participants with no SMI have previously received homelessness services prior to enrolling in Street Outreach services.
• Within one year of enrolling in Street Outreach, 40% of participants with a PSD diagnosis are enrolled in some type of housing program, including 33.5% who enrolled in Interim Housing and 6.1% who enrolled in either Rapid Re-housing or Permanent Supportive Housing.

“There are a many reasons why people fall into homelessness. Individuals with certain types of mental illness, including psychotic spectrum disorders in particular, often enter homelessness as a result of their illness. This study suggests that roughly 10% of the homeless population suffers from a psychotic spectrum disorder. We must be sure that resources are in place to meet the needs of this group to help them access care and exit homelessness,” said Dr. Jonathan Sherin, Director of L.A. County Department of Mental Health.

“Every day, our outreach teams encounter people with severe mental illness experiencing unsheltered homelessness and struggle to provide them with the help they need. This report underscores the importance of having qualified, credentialed mental health professionals who can connect people experiencing unsheltered homelessness and severe mental illness to the treatment they need,” said Molly Rysman, Acting Co-Executive Director of LAHSA. “We hope the results of this study help increase the resources needed to help all of our unsheltered neighbors get on a path to stability and good health.”

“There’s a lot of misperceptions around mental illness and homelessness,” explains Janey Rountree, Executive Director at the California Policy Lab’s UCLA site, and a co-author of the new report. “What we found is that more than eighty percent of L.A. residents seeking homelessness services had not been diagnosed with a serious mental illness by the County in the five years prior to them seeking homelessness services. However, about 4,500 people who are living on the street had been previously diagnosed with psychotic spectrum disorder, and to help those individuals, there will need to be deep, sustained, and coordinated effort to connect them with the health, housing, and other services they will need in order to exit homelessness.”

Additional background
This new analysis updates a similar, 2021 analysis of Street Outreach enrollment data. Personal identifiers in DHS and DMH data were removed prior to CPL receiving the data. Personal identifiers in HMIS data were removed prior to any analysis. Only aggregate PIT count data is used.

CPL’s work was funded by the Los Angeles County Department of Mental Health (DMH) + UCLA Public Partnership for Wellbeing and was a collaboration between CPL, DMH and the Los Angeles Homeless Services Authority (LAHSA).

Research limitations: Please see the full report for more details on these limitations and on the research methodology. The data used in this analysis have important limitations and do not provide a complete picture of the service and housing needs for this group. For example, the report does not include data to observe County services involving diagnoses of Substance Use Disorder (“SUD”), and some psychotic symptoms are likely to be associated with SUD. In addition, if someone receives services or treatment outside of DMH or DHS, those service visits are not captured by the data for this study. This may result in an under-estimate of the prevalence of SMI. Importantly, service visits and their associated clinical diagnoses do not determine a person’s level of functioning or illness severity, which are significant factors for understanding the service and housing needs of individuals experiencing homelessness. Finally, while the research team could observe enrollments in housing programs included in the homeless services data, they do not have data on certain housing programs, including enriched residential facilities (e.g., Board and Care, Adult Residential Facilities, Residential Facilities for the Elderly), or placements in acute or subacute settings (e.g., hospitals, Institutions of Mental Disease, and nursing homes).


The California Policy Lab creates data-driven insights for the public good. Our mission is to partner with California’s state and local governments to generate scientific evidence that solves California’s most urgent issues, including homelessness, poverty, criminal justice reform, and education inequality. We facilitate close working partnerships between policymakers and researchers at the University of California to help evaluate and improve public programs through empirical research and technical assistance.

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