Young drivers at risk of crash hours after cannabis use, study finds

(Wikimedia Commons)

A new study says the ability of young drivers declines significantly after inhaling cannabis, even five hours after consumption.

The study was conducted by the Research Institute of the McGill University Health Centre (RI-MUHC) and McGill University. It was funded by the Canadian Automobile Association (CAA) and published on Monday in the Canadian Medical Association Journal (CMAJ).

“It can affect your reaction time, concentration, decision-making, and the ability to judge distance to other vehicles, pedestrians, and cyclists,” said CAA Saskatchewan’s Director of Corporate Communications and Public Relations, Christine Niemczyk.

While the young drivers’ impairment wasn’t significant with no distractions, their abilities deteriorated in realistic conditions.

The participants, ages 18-24, were tested using a driving simulator.

They were all occasional cannabis users, who have used it within the past three months, but no more than four times a week.

Each participant inhaled 100 milligrams of dried cannabis flowers with a medical grade vaporizer. A typical joint holds 300 to 500 milligrams of dried cannabis.

Their driving was randomly tested one, three and five hours later.

Even before the legalization of recreational cannabis on Wednesday, it’s second to alcohol for substances involved in impaired driving collisions.

It’s also the most common drug found mixed with alcohol in car accidents.

Full details of the study are available on the CMAJ’s website.