Adults who have dyslexia may be more likely to report they were physically abused before they turned 18 than their peers without dyslexia, according to a recent study.

Researchers from the University of Toronto and the University Of North Carolina School Of Medicine in Chapel Hill found that more than one-third of adults with dyslexia report they were physically abused before they turned 18. In contrast, seven percent of those without dyslexia reported that they had experienced childhood physical abuse.

"Even after accounting for age, race, sex and other early adversities such as parental addictions, childhood physical abuse was still associated with a six-fold increase in the odds of dyslexia" researchers said in the study.

For the study, investigators examined a representative sample of more than 13,000 adults aged 18 and older in the 2005 Canadian Community Health Survey including 1,020 respondents who reported that they had been physically abused during their childhood and 77 who reported that they had been diagnosed by a health professional with dyslexia.

"Our data do not allow us to know the direction of the association. It is possible that for some children, the presence of dyslexia and related learning problems may place them at relatively higher risk for physical abuse, perhaps due to adult frustrations with chronic learning failure" Stephen Hooper, co-author of the study, said in a statement. "Alternatively, given the known association between brain dysfunction and maltreatment, it could be that the experience of physical abuse may also contribute to and/or exacerbate such learning problems, secondary to increased neurologic burden."

The results were in a study published online this week in Journal of Interpersonal Violence.

Esme Fuller-Thomson, professor and co-author of the study said that although it is unknown know if the abuse-dyslexia association is causative, "it is important that primary health care providers and school-based practitioners working with children with dyslexia screen them for physical abuse."