Impact of cannabis decriminalization on selected psychotic disorders: a retrospective analysis at the Center for Mental Health and Prevention of Addiction (2013–2023) in Tbilisi
L. Jishkariani, D. Zurabashvili, K. Gigolashvili, N. Jibuti, K. Jmukhadze, G. LezhavaIntroduction
Cannabis decriminalization raises concerns about its psychiatric impact, particularly on psychosis risk. As cannabis became decriminalized in Georgia in 2018, questions emerged regarding changes in substance-related and acute psychotic disorders. Examining these trends is essential to guide prevention, treatment, and policy in a shifting drug landscape.
Objectives
This study aims to:
assess changes in rates of substance-associated psychoses following Georgia’s 2018 cannabis decriminalization; examine diagnostic trends in acute/transient psychoses and cannabinoid-related disorders; explore clinical and policy implications of observed patterns.
Methods
A retrospective review was conducted of all adult psychiatric inpatient admissions (n = 12,680) at the Tbilisi Mental Health and Prevention of Addiction Center between 2013 and 2023. Unique first-time cases diagnosed with F23.0 (n = 789), F20.0 (n = 2,359), and F06.2 (n = 490) were extracted. Cases were stratified into pre-decriminalization (2013–2018) and post-decriminalization (2019–2023) periods. Substance use status, sex distribution, and diagnostic trends were analyzed descriptively.
Results
Following decriminalization, the number of unique ATPD cases tripled (from 195 to 594). Substance-related psychotic cases increased fourfold (from 243 to 907), with cannabis implicated in over 70% of post-2018 substance cases. The proportion of psychosis cases involving substance use rose from 9.6% pre-2018 to 81.4% post-2018. Cannabis-only use increased 4.2-fold; polysubstance use increased 3.2-fold. Substance-using cases were overwhelmingly male (96%). F20.0 and F06.2 incidence showed a relative decline, potentially reflecting chronicity and under-detection in inpatient settings.
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