Almost one-third of Canadian adults have experienced child abuse, according to a new study that also found an association between child abuse and certain mental disorders.

The study, published Tuesday in the Canadian Medical Association Journal, found that 32 per cent of Canadian adults have experienced child abuse -- defined by the study authors as physical abuse, sexual abuse or exposure to intimate partner violence (having witnessed their parents or guardians hitting each other).

The study, which analyzed data from 23,395 participants in the 2012 Canadian Community Health Survey, is the first nationally representative study on child abuse and mental disorders in Canada.

"That might include more difficulties with mood disorders and anxiety disorder,” University of Manitoba child abuse researcher Tracie Afifi told CTV News. “They may be more likely to use substances including alcohol and drugs.”

The participants in the survey were 18 years old or older, and were representative of Canadians living in the 10 provinces. The study excluded Canadians living in the three territories, residents in indigenous communities, people living in institutions and full-time members of the Canadian Forces.

The respondents were asked whether they had experienced specific forms of physical or sexual abuse before they turned 16 years old. For example, respondents were asked if they had been slapped, spanked, pushed, kicked, punched or choked as a child.

They were also asked if there had been past attempts to force them into unwanted sexual activity, or if they had experienced unwanted sexual activity, such as grabbing, kissing or fondling.

Dr. Tracie Afifi, one of the study's co-authors and a professor from the University of Manitoba, said that the results of the study point to the "urgent need" to address child abuse.

"From a public health standpoint, these findings highlight the urgent need to make prevention of child abuse a priority in Canada," she said in a statement.

The study also found the following:

  • Physical abuse was the most common form of abuse (32 per cent), followed by sexual abuse (10 per cent) and exposure to intimate partner violence (eight per cent).
  • Physical abuse is more common in men (31 per cent) than in women (21 per cent).
  • Sexual abuse is more common in women (14 per cent) than in men (six per cent).
  • Exposure to intimate partner violence is also more common in women (nine per cent) than in men (seven per cent).
  • Canadians between the ages of 35-64 were more likely to report having been abused compared to those between the ages of 18-34.
  • The prevalence of child abuse was highest in the western provinces, with Manitoba having the highest rate (40 per cent), followed by British Columbia (36 per cent) and Alberta (36 per cent).
  • Newfoundland and Labrador had the lowest reported rate of child abuse at 21 per cent.

The study also examined the relationship between child abuse and a number of mental conditions and disorders, which were either self-reported by the survey participants or diagnosed through interviews.

Jean-Paul Bedard says the sexual abuse he suffered as a child left him coping with addiction and mental health disorders as an adult.

"I ended up going into a treatment program to deal with the addictions and at the same time I was dealing with a lot of mental health issues, in terms of severe bipolar depression," Bedard said.

He has since become a child abuse advocate and he recently ran the Boston Marathon to raise money for a special treatment centre for adult victims of abuse.

"It's not something I have to put away," he said. "It's more of a matter of learning to live with it in a healthy way."

Some of the specific mental health conditions and disorders examined included depression, bipolar disorder, drug and alcohol abuse and dependence, obsessive-compulsive disorder, post-traumatic stress disorder, attention deficit disorder, having suicidal thoughts and suicide attempts.

The study's authors found that all three types of child abuse were associated with all types of mental conditions, whether diagnosed through interviews or self-reported. All three types of child abuse were also associated with suicidal ideation and suicide attempts.

Even the least severe type of physical abuse studied by the authors – defined as being slapped on the face, head or ears, or hit or spanked with something hard – showed a strong association with all mental conditions, the authors found.

The results of the study are similar to findings from similar national surveys from the U.S., as well as findings from smaller studies from Ontario and Quebec.

The authors conclude that healthcare providers working in the field of mental health should be able to assess patients for exposure to abuse. Also, clinicians should be familiar with the mandatory reporting requirements in their respective province or territory.

"From a public health standpoint, these findings highlight the urgent need to make prevention of child abuse a priority in Canada," they write.

"Success in preventing child abuse could lead to reductions in the prevalence of mental disorders."

With a report from CTV's medical specialist Avis Favaro and producer Elizabeth St. Philip