Research Profile – Beyond Breathalysers

McGill researchers are helping identify people at risk for repeat DWI offences.

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Driving while intoxicated (DWI) remains a significant problem in Canada. As recently as 2009, more than 2,200 people died in traffic crashes on Canadian roads, and an additional 172,883 people were injured. About a third of the crashes involved an impaired driver.

The key to fixing this problem may lie in understanding what causes some drivers to be repeat offenders. “After years of improvements in DWI rates, further reductions have stalled since early 2000,” says Dr. Thomas Brown, assistant professor of psychiatry at McGill University. Now, the challenge is to figure out how to get those rates dropping again.

He notes that “there is a ‘hard-core’ group of repeat offenders, and these are the toughest people to get to and change… A multi-faceted approach is needed.” Dr. Brown works with a multidisciplinary team studying the causes of DWI, as well as programs and policies aimed at prevention. The research team includes people from Quebec’s licensing authorities and other decision makers, as well as researchers in traffic safety, addiction, criminology, behavioural neuroscience, psychiatry, epidemiology and other fields.

Currently, DWI prevention programs are mostly aimed at deterrence, and may include everything from license suspension to more severe consequences such as hefty fines and criminal charges. In Quebec, repeat offenders are required to enter either a DWI education program or a comprehensive assessment system in order to re-acquire their driver’s license.

Dr. Brown and his team have been studying the characteristics of repeat offenders, and why the current prevention programs aren’t working for this group. They’ve found that while not all repeat DWI offenders have serious drinking problems, these drivers tend to have higher blood alcohol levels than other impaired drivers, and they demonstrate a limited ability to recognize risks associated with their alcohol use.

The research team also found that repeat offenders often delay the process for getting their license back. This trend is troubling, because delaying relicensing means these people are driving unlicensed and uninsured, and they aren’t getting the exposure they may need to intervention programs.

Dr. Brown’s team found that people who delay relicensing had more past convictions for driving under the influence, tended to drive more kilometers under the influence, were likely to have received past substance abuse treatment, and performed more poorly on neurocognitive tests for visual memory and behavioural inhibition than people who went through relicensing more willingly. They reported that they delayed renewing because of the high cost of getting back their license, the availability of alternate transportation, or simply because of lack of interest. Overall, results from the team’s studies show that delayed relicensing arises from a complex web of practical, psychological, social-economic and neuropsychological factors.

Other studies by the team suggest that how a person’s body responds to stress may influence their risk of re-offending. People who’ve been charged with multiple DWIs tend to show lower levels of the ‘stress hormone’ cortisol when in a stressful situation. Preliminary data collected by researchers at the University of Sherbrooke suggest that this is also seen in novice drivers who seem to acquire safe driving skills more slowly.

This pattern of stress response is associated with genetic factors in alcohol misuse and involvement in other risk-taking behaviours as well. In other words, biological markers, such as cortisol levels and expression of specific genes, could potentially be used to better understand and detect risk-taking in some drivers.

In a study of a prevention approach to DWI, young adult offenders responded better to a 30-minute brief motivational interviewing session than older offenders. Over a five-year period, they were less likely to be arrested again for risky driving than offenders who were simply given information about drunk driving.

The researchers are using their findings to assist Quebec’s licensing authorities improve their policies and programs for preventing DWI. “We are proud to be partners in the effort to improve safety on Canadian roads,” says Dr. Brown.

“There is a ‘hard-core’ group of repeat offenders, and these are the toughest people to get to and change… A multi-faceted approach is needed.”
– Dr. Thomas Brown, McGill University