TORONTO -- Marijuana use may be down among teens and young adults, a new report from Statistics Canada suggests.

Younger Canadians are still the biggest consumers of marijuana, with a third of 18- to 24-year-old respondents reporting they had used marijuana or hashish in the past year.

But the percentage of teens between the ages of 15 and 17 who reported having ever used marijuana dropped to 25 per cent in 2012 from nearly 40 per cent in 2002, according to the report, published Wednesday in the monthly Health Reports.

And the percentage of 15- to 17-year-olds who reported having used marijuana in the previous 12 months dropped by about 30 per cent over the 10-year period, said co-author Michelle Rotermann, a senior analyst with the statistical agency.

As well, the proportion of 18- to 24-year-olds who reported having used the drug at least once fell to about 54 per cent from 62 per cent over the same time frame.

The report is based on data collected during the 2012 Canadian Community Health Survey on mental health. Over 25,000 Canadians aged 15 and older responded to the survey; the sample is considered representative of about 28 million Canadians over the age of 15.

The survey asked respondents if they had ever used marijuana or hashish, and if they had used either drug in the previous 12 months.

The data are self-reported and not verified. The authors note that means some respondents may have modified their answers to give what they thought is a socially acceptable reply. That's a recognized and routine problem with self-reported data, especially about behaviours society may frown on.

The data clearly show that marijuana is more of a guy thing than a girl thing.

"That is a fairly consistent finding that we find in all age groups and ages combined, that use of marijuana is more common among males than females -- and often by 50 per cent," Rotermann said in an interview from Ottawa.

More than 49 per cent of males reported having used marijuana at some point in their life, compared to 36 per cent of females. And daily use was more common among males; 2.4 per cent of males reported using marijuana every day, double the percentage of females who reported daily use.

The findings also call into question the suggestion that marijuana is a gateway drug that leads to use of harder drugs.

The vast majority of respondents who said they used drugs like cocaine or heroin also reported using marijuana. But most marijuana users reported they had not used other illicit drugs, either in the past year or in their lifetimes.