SUBSTANCE USE PROFILES IN FIRST-EPISODE PSYCHOSIS AND PSYCHOSIS-RISK PATIENTS - RESULTS OF THE TURKU EARLY PSYCHOSIS STUDY (TEPS)

ABSTRACT Background: Substance use is known to be prevalent in first-episode psychosis (FEP). Substance use is also a known risk factor for psychosis in vulnerable individuals and forms one of the treatment targets in preventive early intervention protocols. Aims: The aim of this study was to evaluate prevalence and detailed characteristics of substance use profiles in patients with FEP and patients with a clinical psychosis risk compared to those in a general population sample. Method: The sample consisted of in- and outpatients recruited from the psychiatric services in South West Finland between years 2011 and 2017. The participants were divided into four groups based on standardized clinical evaluation: 1) patients with FEP (n=130); 2) patients with clinical high risk for psychosis (CHR-P) assessed with the Structured Interview for Psychosis-Risk Syndromes (SIPS) (n=61); 3) patients with clinical psychosis risk assessed by the clinical treatment team but not fulfilling the SIPS criteria (CHR-N) (n=44); and 4) general population controls (n=121). Past and current substance use data was collected using questionnaires. Results: Across all study groups, current regular cigarette smoking, hazardous alcohol use and illicit drug use during lifetime and during the past 12 months was most common in the FEP group. Lifetime and past 12 months cannabis use was significantly more common only in the FEP group compared to the control group. However, other illicit drug use during both lifetime and past 12 months was more common in all patient groups compared to the control group. While current regular smoking was more common in all patient groups compared to the control group, hazardous alcohol use defined as AUDIT score ≥8 points was not. Conclusions: Substance use is highly prevalent in first-episode psychosis and in patients with a clinically defined risk for psychosis. Thus, detailed screening of substance use in this vulnerable population is an important clinical priority in integrated early intervention strategies aimed at improving patient outcomes.