CMAJ

Antipsychotic adherence halves crash risk in drivers with schizophrenia

June 12, 2025

Optimizing antipsychotic adherence may significantly reduce motor vehicle crash risk among drivers with schizophrenia. Consideration of antipsychotic adherence could inform clinical counseling and policy decisions regarding fitness-to-drive assessments in this population.

Study details: This population-based case-crossover study analyzed administrative health and driving records from British Columbia, Canada, over a 15-year period. The cohort included 1,130 individuals with schizophrenia who were involved as drivers in police-attended motor vehicle crashes and had filled outpatient antipsychotic prescriptions in the two years prior. Adherence was quantified using the medication possession ratio (MPR) in the 30 days before the crash (pre-crash interval) and compared with a 30-day control interval one year earlier. Conditional logistic regression adjusted for confounders was used to assess the association between antipsychotic adherence and crash risk.

Results: Mean antipsychotic MPR was lower in the pre-crash interval (0.69) compared with the control interval (0.76). Perfect adherence to antipsychotic medication was associated with a 50% reduction in the odds of a crash compared with complete nonadherence (adjusted odds ratio, 0.50, 95% confidence interval, 0.38–0.66). This association was consistent across subgroups defined by sex, age, and substance misuse history.

Source:

Staples JA, et al. (2025, June 8). CMAJ. Antipsychotic treatment adherence and motor vehicle crash among drivers with schizophrenia: a case-crossover study. https://pubmed.ncbi.nlm.nih.gov/40490284/