The Toronto-based Centre for Addiction and Mental Health says that amounted to 2.3 per cent of Ontario's adult population.
CAMH says its mental health survey, started in 1977, was based on responses from 3,021 Ontario adults who were asked specifically about suicide for the first time.
"We felt it was important to include a specific question about suicide so that we can better understand the scope of the issue," said Dr. Hayley Hamilton, CAMH scientist and co-principal investigator of the study.
The centre says the results also reveal a sharp increase in self-rated poor mental health, from 4.7 per cent in 2003 to 7.1 per cent in 2013, or 716,000 Ontario adults.
CAMH says the increase was especially evident during the past five years among those aged 18 to 29, rising from about three per cent in 2009 to 12 per cent in 2013.
Hamilton calls the rising rates among young adults a troubling trend.
"This could be an indication that young adults and youth transitioning to adulthood need more support from family, friends, and health professionals when it comes to their mental health and overall wellbeing."
The CAMH study also shows the rate of cannabis use among Ontario adults climbed to 14 per cent last year from 8.7 per cent in 1996. And, while 40 per cent of 2013 users report using cannabis less than once per month, the percentage reporting daily use was 19 per cent.
"The fact that we are seeing a steady increase in cannabis ... underscores the need for a public health approach to cannabis control," said Dr. Robert Mann, CAMH senior scientist and co-principal investigator of the CAMH Monitor.
In early October, CAMH called for marijuana to be legalized with strict conditions. It said this was the best way to reduce the harms associated with its use, such as respiratory diseases and impaired cognitive abilities.
However, Ontario Health Minister Eric Hoskins refused to take a position on the CAMH recommendation, insisting it is a federal issue. The Canadian Public Health Association welcomed the CAMH call to legalize pot, saying the war on drugs has failed and done more damage than any possible good.
CAMH says the survey also found that cigarette smoking rates among adults have declined from 27 per cent in 1996 to 17 per cent last year. It says daily smoking showed a similar decline, from 23 per cent in 1996 to 13 per cent in 2013.
When it comes to daily alcohol use, CAMH says nearly one in four drinkers reported that they exceed Canada's low-risk drinking guidelines.
The number of adults who reported having consumed alcohol at least once a day rose from five per cent in 2002 to 8.5 per cent in 2013. The results also showed that women are drinking at higher rates, from 2.6 per cent in 2001 to 5.6 per cent in 2013.
"We continue to see that more women are drinking more frequently," said Dr. Mann.
"This increase is worrying because heavy alcohol use is associated with a number of health risks, including cancer."
But while alcohol consumption rates appear to be rising, CAMH says rates of drinking and driving continue to drop. Its survey suggests that from 1996 to 2013, drinking and driving fell by more than half, from 13 per cent to five per cent.
The annual survey also found that the use of non-medical prescription opioids by adults plunged from 7.7 per cent in 2010 to 2.8 per cent last year. However, use among 18-29 year olds held stable at about seven per cent over the same period.
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