Older drivers who use prescription psychoactive drugs such as benzodiazepines may be five times more likely to be involved in a motor vehicle accident, a new Curtin University study has found.

The study, Psychoactive Medications and Crash Involvement Requiring Hospitalization for Older Drivers: A Population-Based Study, concluded that the use of psychoactive medications, particularly benzodiazepines and anti-depressants, increased the likelihood of involvement in motor vehicle crashes for older drivers.

Head of the Curtin Monash Accident Research Centre (C-MARC) study, Associate Professor Lynn Meuleners, said the level of impairment caused by benzodiazepines and some anti-depressants could be compared to that of drinking alcohol.

“The role of alcohol in traffic crashes has been established, but for prescribed medications there is limited current, evidence-based information,” A/Prof Meuleners said.

“The usage of medications, particularly benzodiazepines and anti-depressants, may contribute to a longer reaction time when faced with the unexpected while driving.

“In this study, older drivers exposed to benzodiazepines were five times as likely to be involved in a hospitalisation crash, and almost twice as likely for drivers exposed to anti-depressants.”

Given that benzodiazepines and anti-depressants are frequently used by people over 60, and polypharmacy (using several drugs at the same time) is also more common among this group, the study's results bear great implications.

A/Prof Meuleners has therefore called for licensing authorities and policy makers to take note of the study’s results and consider the implications of the findings when creating rules and policy measures for older drivers.

“Inclusion of such medications on medical reporting forms for older drivers to licensing authorities would enable ongoing surveillance that would provide a more comprehensive evidence base of the need for stricter regulatory policies.”

The research, recently published in the Journal of the American Geriatrics Society, involved more than 600 individuals aged 60 and older who were hospitalised as the result of a motor vehicle crash between 2002 and 2008 in Western Australia.