One in 10 drivers in Grades 10 to 12 reported getting behind the wheel within an hour of using marijuana at least once during the past year, the latest Ontario Student Drug Use and Health Survey says.
That's compared with four per cent who reported doing so after having two or more drinks of alcohol, the data released Wednesday show.
More than 10,000 Ontario students in Grades 7 through 12 from close to 200 schools participated in this year's study. They answered anonymous questionnaires between November of last year and March.
The survey, administered by York University's Institute for Social Research for the Centre for Addiction and Mental Health, has been conducted every two years since 1977.
It found that in recent years, only the percentage of students reporting they get high on over-the-counter cough and cold medication has increased significantly.
Just shy of one in 10 students — 9.7 per cent — reported abusing cold medication in the past year in 2013, up from 7.2 per cent in 2009, the study says.
Meanwhile, students' reported use of 13 other substances — including alcohol, cigarettes, cocaine and methamphetamine — has dropped significantly between 1999 and this year, it says.
Students in Grades 9 through 12 also reported less non-medical use of prescription drugs: 15.2 per cent this year from 23.5 in 2007.
And more students reported abstaining from drugs, alcohol and tobacco altogether in the past year than they did in 1999 — 37 per cent, up from 27 per cent.
"Alcohol use has been declining gradually since about 1999 and has shown a further decline between 2011 and 2013, reaching a historically low level," the study reads.
About half the respondents reported drinking alcohol in the past year, and one in five reported binge drinking in that time, it says. Binge drinking is defined as consuming five or more drinks on one occasion.
By comparison, nearly a quarter of the respondents reported using marijuana in the past year, and about three per cent reported using it daily.
Caffeinated energy drinks were also popular among those surveyed, with about 40 per cent saying they had at least one in the past year and 12 per cent saying they had at least one in the past week, the report says.
Boys were more likely than girls to report using energy drinks, marijuana, over-the-counter drugs, a hookah pipe, smokeless tobacco, attention deficit hyperactivity disorder medication, methamphetamines or hallucinogens like mushrooms or salvia in the last year.
The study also shows reported use of most drugs, with the exception of inhalants, was more prevalent in higher grades.