Antipsychotic treatment and average time to discharge in patients with first-episode nonorganic psychosis and cannabis use

Abstract

Objective: Cannabis-Induced Psychotic Disorder (CIPD) is a newly identified disorder that is recognized under the Diagnostic And Statistical Manual Of Mental Disorders Fifth Edition (DSM-5), but does not currently have guidelines for treatment. Evidence regarding CIPD treatment with antipsychotics is limited to case reports; thus, prescribing patterns may vary. At Trillium Health Partners (THP), some psychiatrists may initiate a scheduled antipsychotic in patients presenting with CIPD, while others may not. The primary objective of this study is to determine whether there was a difference in average time to discharge between CIPD patients who received antipsychotic treatment within five days of first psychiatry consult, compared to those who did not. Secondary objectives include percent distributions and average times to discharge for antipsychotics prescribed, and the percentage of patients discharged against medical advice. Methods: This retrospective chart review includes data from 66 charts of adult patients admitted to THP psychiatry units for a first-episode nonorganic psychosis with a positive cannabinoid urine test. Results: Current practice at THP reflects a preference for scheduled antipsychotic treatment within five days of psychiatric consult (64%) in patients presenting with CIPD. The average time to discharge in the group who received scheduled antipsychotic treatment within five days was 23 hours less than the group that did not; however, the t-score value (0.457) was smaller than the critical t-value (2.03) which suggests there is no true difference between groups for this outcome. Olanzapine was the most prescribed antipsychotic, and each antipsychotic was associated with a different average time to discharge. Conclusions: This descriptive study suggests that antipsychotic treatment within five days of first psychiatric consult may not result in a true difference in average time to discharge compared to no treatment. The findings may inform larger studies that could be better powered to identify cause-and-effect relationships and influence future CIPD treatment guidelines.