Taking antipsychotic medications lowers crash risk for drivers with schizophrenia

Taking antipsychotic medications as prescribed lowers the risk of a car crash for drivers with schizophrenia, according to new research published in CMAJ (Canadian Medical Association Journal) https://www.cmaj.ca/lookup/doi/10.1503/cmaj.250020.

Schizophrenia can cause hallucinations and disorganized behaviour that affect the ability to safely operate a motor vehicle. Most people with schizophrenia are prescribed antipsychotic medications that improve many of these symptoms. Researchers hypothesized that these medications may also reduce the risk of a motor vehicle crash - but only if patients continue to take the medication as prescribed.

Dr. John A. Staples and colleagues at the University of British Columbia in Vancouver, BC, used 20 years of population-based health and driving data to examine 1130 motor vehicle crashes involving drivers with a diagnosis of schizophrenia and prior treatment with antipsychotics. They found that taking antipsychotic medication as prescribed significantly reduced the odds of a crash.

We found that perfect adherence to antipsychotic medication (relative to complete nonadherence) was associated with a 50% reduction in the odds of a crash. We believe our results suggest that antipsychotic medications reduce crash risk among individuals with schizophrenia."

Dr. John A. Staples, University of British Columbia

The findings have important implications.

"Our results provide one more reason for doctors and family members to encourage people with schizophrenia to take their antipsychotics as prescribed. We think our results also suggest that health systems should put more resources into programs to support antipsychotic adherence among people with schizophrenia," says Dr. Staples.

He adds, "If a driver with schizophrenia isn't taking their medications as prescribed, should their driver's licence be temporarily suspended? This approach deserves some consideration. But we also know that people with schizophrenia are often marginalized, with limited opportunities for employment and social engagement. Taking away their driver's licence might make them more isolated. We think more research is needed so that policy-makers can understand these risks before enacting a policy that might be coercive or harmful."

Clinicians can find current, evidence-based guidance on assessing fitness to drive in patients with conditions that may affect driving ability in Determining Medical Fitness to Operate Motor Vehicles: CMA Driver's Guide, 10^th edition.