Disruptive behaviour disorders in male teenagers associated with increased risk of road crashes

These are the findings of a study by Donald Redelmeier and colleagues from the University of Toronto, Toronto, Canada, and published in this week's PLoS Medicine. Male teenagers are the single most risky population group of drivers, with twice the collision rate of the general population, despite low amounts of driving and good general health.

The authors conducted a 7-year study in Ontario, Canada, of consecutive males aged between 16 years and 19 years who were admitted to hospital as the result of a road traffic crash and those who were admitted to the same hospitals during the same time interval for appendicitis. During the study period, 3421 male teenagers were admitted to hospital as the result of a road traffic crash and 3812 male teenagers were admitted to hospital for appendicitis. A history of disruptive behaviour disorders was more frequent among male teenagers admitted for road traffic crashes than controls (767 of 3421 v 664 of 3812) giving an odds ratio of 1.37. This higher risk was still present after the authors took factors such as age, social status and home location into account.

This study did not document who was "at fault"; hence, perhaps behavioural disorders impair a teenager's ability to avoid a mishap initiated by someone else. The authors stress that their results do not justify withholding a driver's license. Instead, the authors suggest that disruptive behaviour disorders could be considered as contributors to road traffic crashes -- similar to epilepsy, diabetes, and some other medical diseases.

The authors conclude: "Greater attention by primary care physicians, psychiatrists, and community health workers might be helpful since practical recommendations might reduce the risk." Specific recommendations include avoiding excess speed, restricting alcohol, minimizing other distractions as well as using seatbelts, keeping distance from other vehicles, and obeying medical advice.