The use of cannabis among school-aged kids in Canada has steadily declined for 12 straight years, and usage is now at the lowest level since the 1980s.

That's just one finding from a comprehensive study, Health Behaviours of School-Aged Children, examining the health behaviours of kids from grades 6 to 10.

Elizabeth Saewyc is a co-author of the study and a professor of nursing at the University of British Columbia.

"What we see is that in 1990, there was about 26 per cent of boys and 24 per cent of girls who had ever tried it," she told On The Coast host Stephen Quinn.

"It peaked at 50 per cent of boys in 2002, and in 1998 it was 40 per cent of girls. But now, it's 23 per cent of both boys and girls."

Saewyc says in addition to the decline in cannabis use, other drug use is down as well — as is smoking, drinking and binge drinking. The only increase the researchers saw was when it came to e-cigarettes.

"E-cigarettes are one of those things that we're beginning to be a little concerned about, because clearly the tobacco use is down, and has been consistently low, but if they're trying e-cigarettes at that level, does that mean we could be seeing a turnaround and smoking will become cool again?"

Other findings give mixed message

The study, conducted by the World Health Organization and the Public Health Agency of Canada, looks at the same measures in children in 44 countries every four years, including eating and exercising habits, physical injuries, and even bullying.

When it comes to mental health, Saewyc says girls are reporting symptoms of depression at a much higher rate than boys — almost double the rate by the time they hit Grade 10, she said.

As well, girls are less likely to report feeling confident than boys, but both boys and girls see their confidence decline as they get older.

"There's no doubt that the social expectations for boys and girls are different and this contributes to stressors in findings like this, but it does suggest a particular focus on girls and young women is warranted," she said.

Other findings from the report included:

  • Kids are eating more fruit.
  • They are drinking fewer soft drinks.
  • As they get older, they tend to eat more fast food.
  • Only one in five kids is getting the recommended 60 minutes of moderate to vigorous activity per day.
  • Levels of obesity and being overweight remained steady since the last study: one in three boys and one in four girls were overweight or obese.

With files from On The Coast

To hear the full story, click the audio labelled: Smoking, cannabis use, and drinking down in teenagers: study