Emergency Department Visits Involving Hallucinogen Use and Risk of Schizophrenia Spectrum Disorder.
Daniel T Myran, Michael Pugliese, Jennifer Xiao, Tyler S Kaster, M Ishrat Husain, Kelly K Anderson, Nicholas Fabiano, Stanley Wong, Jess G Fiedorowicz, Colleen Webber, Peter Tanuseputro, Marco Solmi
JAMA psychiatry February 1, 2025 DOI: 10.1001/jamapsychiatry.2024.3532
Summary
Individuals visiting emergency departments (ED) for hallucinogen use face a staggering 21 times greater risk of developing schizophrenia spectrum disorders (SSD) within three years compared to the general population. An analysis of over 9 million individuals in Ontario revealed that 0.1% had ED visits related to hallucinogens, with a dramatic 86.4% increase in such visits from 2013 to 2021. Notably, those with hallucinogen-related visits had a 3.99% SSD diagnosis rate, compared to just 0.15% in the broader population, highlighting significant clinical concerns.
Abstract
Interest in and use of hallucinogens has been increasing rapidly. While a frequently raised concern is that hallucinogens may be associated with an increased risk of psychosis, there are limited data on this association. To examine whether individuals with an emergency department (ED) visit involving hallucinogen use have an increased risk of developing a schizophrenia spectrum disorder (SSD). This population-based, retrospective cohort study (January 2008 to December 2021) included all individuals aged 14 to 65 years in Ontario, Canada, with no history of psychosis (SSD or substance induced). Data were analyzed from May to August 2024. An incident ED visit involving hallucinogen use. Diagnosis of SSD using a medical record-validated algorithm. Associations between ED visits involving hallucinogens and SSD were estimated using cause-specific adjusted hazard models. Individuals with an incident ED visit involving hallucinogens were compared with members of the general population (primary analysis) or individuals with ED visits involving alcohol or cannabis (secondary analysis). The study included 9 244 292 individuals (mean [SD] age, 40.4 [14.7] years; 50.2% female) without a history of psychosis, with a median follow-up of 5.1 years (IQR, 2.3-8.6 years); 5217 (0.1%) had an incident ED visit involving hallucinogen use. Annual rates of incident ED visits involving hallucinogens were stable between 2008 and 2012 and then increased by 86.4% between 2013 and 2021 (3.4 vs 6.4 per 100 000 individuals). Individuals with ED visits involving hallucinogens had a greater risk of being diagnosed with an SSD within 3 years compared with the general population (age- and sex-adjusted hazard ratio [HR], 21.32 [95% CI, 18.58-24.47]; absolute proportion with SSD at 3 years, 208 of 5217 with hallucinogen use [3.99%] vs 13 639 of 9 239 075 in the general population [0.15%]). After adjustment for comorbid substance use and mental health conditions, individuals with hallucinogen ED visits had a greater risk of SSD compared with the general population (HR, 3.53; 95% CI, 3.05-4.09). Emergency department visits involving hallucinogens were associated with an increased risk of SSD within 3 years compared with ED visits involving alcohol (HR, 4.66; 95% CI, 3.82-5.68) and cannabis (HR, 1.47; 95% CI, 1.21-1.80) in the fully adjusted model. In this cohort study, individuals with an ED visit involving hallucinogen use had a greater risk of developing an SSD compared with both the general population and with individuals with ED visits for other types of substances. These findings have important clinical and policy implications given the increasing use of hallucinogens and associated ED visits.