Adults who have ADHD are much more likely to report they were sexually and physically abused before they turned 16 than their peers without ADHD, according to a new study from researchers at the University of Toronto.

Among women, 34 per cent of those with ADHD reported they were sexually abused before they turned 18. In contrast, 14 per cent of women without ADHD reported that they had experienced childhood sexual abuse. Twice as many women with ADHD reported that they had experienced childhood physical abuse than women without this condition (44% vs 21%).

"These findings suggest there is a silent epidemic of abuse among people and particularly women with ADHD," says co-author Esme Fuller-Thomson, professor and Sandra Rotman Endowed Chair at U of T's Factor-Inwentash Faculty of Social Work and the Faculty of Medicine.

Fuller-Thomson's research also noted that a greater percentage of men with ADHD than men without ADHD reported that they were sexually abused (11 per cent vs six per cent) or physically abused (41 per cent vs 31 per cent) during their childhood.

Investigators examined a nationally representative sample of 12,877 women and 10,496 men in the 2012 Canadian Community Health Survey-Mental Health.

Fuller-Thomson emphasized that the data cannot clarify the direction of the association. "It may be that early maltreatment affects neurobiological development," says Fuller-Thomson. "It is also possible that children with ADHD are more vulnerable to abuse."

The results appeared in a study published online in Child Abuse & Neglect.

"The questions in the survey did not identify who was abusing the children, it could have been a family member or a non-related adult" said study co-author, Danielle Lewis, a graduate student in U of T's Masters of Social Work program. "No matter who is the perpetrator, it is very important that health professionals working with children with ADHD screen them for sexual and physical abuse."