First vs. multiple cannabis-induced psychotic episodes: Is inpatient treatment any different?

INTRODUCTION: Recent studies reported very high cumulative risk for a patient who had cannabis-induced psychosis to be diagnosed with a schizophrenia spectrum disorder. OBJECTIVES: We aim to compare sociodemographic and clinical characteristics, treatment and discharge plan in cannabis-induced first psychosis episode (CI-FEP) vs. multiple cannabis-induced psychotic episodes (CI-MEP) inpatients. METHODS: Retrospective observational study of inpatient episodes with a discharge diagnosis of cannabis-induced psychosis between January 1(st), 2018 and December 31(st), 2019 in the Psychiatry Service of CHUSJ. Descriptive analysis of the results was performed using the SPSS software, version 26.0. RESULTS: Our sample included 61 inpatients, 19 (31.1%) with CI-FEP and 42 (68.9%) with CI-MEP. CI-MEP group had a median of 1±0,234 previous hospital admissions. CI-MEP group has 10,0 higher odds of being discharged in outpatient compulsory treatment (CI 95% 1,21-82,50, p=0,013) and 6.0 odds of being treated with long-acting injectable antipsychotics (LAIAP) (CI 95% 1,79-20,31, p=0,002) when compared to CI-FEP group. Having multiple cannabis-induced psychotic episodes was associated with future admissions to psychiatry unit (OR 4,85 (95% CI 1,23-19,15, p=0,018). We found no statistically significant differences regarding the sociodemographic and clinical characteristics, use habits and discharge plan between the two groups. CONCLUSIONS: Patients with multiple psychotic episodes due to cannabis use are more likely to have a LAIAP prescription, be discharged in compulsory outpatient regimen and be readmitted in to psychiatric inpatient unit. Considering the prevalence of CI-MEP and the risk of chronicity, we need integrative treatment programs to address the specificities of these patients.