Substance Use in Clinical High-Risk for Psychosis

Cheryl Y. S. Foo (1-4), Lauren A. Utter (2-4), Catherine Leonard (1), Julie M. McCarthy (4,5), Corinne Cather (1,2,4), Daphne Holt (1-4), Jacqueline A. Clauss (2,3,6,7)
1. Center of Excellence for Psychosocial and Systemic Research, Department of Psychiatry, Massachusetts General Hospital
2. Psychosis Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital
3. Resilience and Prevention Program, Department of Psychiatry, Massachusetts General Hospital
4. Department of Psychiatry, Harvard Medical School
5. Division of Psychotic Disorders, McLean Hospital
6. Department of Psychiatry, University of Maryland Medical School
7. Maryland Psychiatric Research Center, University of Maryland

Background: Individuals at clinical high-risk for psychosis (CHR-P) have an elevated risk for developing serious mental illnesses, including psychotic disorders, and severe mood and anxiety disorders. Co-occurring substance use predicts worse symptom and functional outcomes, with cannabis use elevating risk of psychotic disorder conversion. This study examined prevalence of lifetime and recent substance use and treatment engagement around substance use in CHR-P programs in Massachusetts.
Method: Individuals referred to CHR-P programs completed a standardized evaluation battery, including self-report substance use measures. Among CHR-P individuals enrolled in care, providers also reported rates of substance use and whether patients who used substances had treatment goals on reducing substance use, utilized substance use pharmacotherapy, or incorporated adjunctive substance use interventions (e.g., tobacco smoking quitline, recovery coaching, Alcoholics Anonymous). Prevalence rates are reported for the MGH RE-SET program, with data from other programs forthcoming.
Results: Fifty-eight individuals completed evaluation for CHR-P between October 2021 to December 2023 (mean age: 17.8 years old; 57% female; 31% met criteria for CHR-P). Thirty-six (62%) had used substances in their lifetime, with cannabis use being the most frequent (n=13, 36%), followed by alcohol (n=9, 25%). Eleven (31%) used vaping devices. Of those who had tried alcohol or cannabis, more than 75% were current users (used at least once in the past three months). Twelve (33%) screened positive for problematic substance use. Three (38%) current RE-SET patients reported using substances, of whom two were interested in reducing substance use and none utilized substance pharmacotherapy or adjunctive interventions.
Conclusion: Over one-third of help-seeking individuals receiving evaluation for CHR-P have recent and problematic cannabis or alcohol use. As early substance use initiation dramatically increases risk of heavier use and dependence especially for psychiatrically vulnerable populations, interventions for preventing the development and progression of substance use disorders in CHR-P is warranted.