Childhood adversities linked to drug or alcohol dependency in adults

Adults who have drug or alcohol dependency have experienced very high rates of early adversities, according to a new study published by University of Toronto researchers. One in five drug dependent Canadian adults and one in six alcohol dependent adults were survivors of childhood sexual abuse. This compares to one in 19 in the general Canadian population. More than one half of substance abusers had been physically abused in childhood compared to one-quarter of those who were not addicted. After accounting for mental illness, poverty and social support, both sexual and physical abuse were associated with twice the odds of drug dependence.

"We found that both direct (physical and sexual abuse) and indirect (witnessing parental domestic violence) forms of childhood victimization are associated with substance abuse" said lead author, Professor Esme Fuller-Thomson, Sandra Rotman Endowed Chair at the University of Toronto's Factor-Inwentash Faculty of Social Work and Institute for Life Course & Aging

"We were surprised that chronic parental domestic violence exposure remained significantly associated with both drug and alcohol dependence, even when we adjusted for childhood maltreatment, depression and most of the known risk factors for substance dependency" said lead author, Professor Esme Fuller-Thomson, Sandra Rotman Endowed Chair at the University of Toronto's Factor-Inwentash Faculty of Social Work and Institute for Life Course & Aging. "In fact, the odds of alcohol dependency among those who witnessed their parents' chronic domestic violence were about 50% higher than those without that exposure, and these odds were similar in magnitude to that of childhood sexual abuse. One in seven adults with drug dependence or alcohol dependence had been exposed to chronic parental domestic violence. This compares to one in 25 in the general population. Parental domestic violence was considered 'chronic' if it occurred 11 or more times before the respondent was age 16."

Further research is needed to understand the pathways through which witnessing chronic parental domestic violence and childhood maltreatment during the respondent's childhood may increase the prevalence of drug and alcohol dependence across the life course. " Fuller-Thomson suggests that "the chronic chaotic and violent home environment may have predisposed individuals to turn to alcohol or drugs as a way of coping."

The study was based upon a representative sample of 21,544 adult Canadians drawn from the 2012 Canadian Community Health Survey-Mental Health components. At some point in their life, 628 of these respondents had been dependent upon drugs and 849 had been dependent upon alcohol.

Co-author and recent MSW graduate, Jessica Roane commented, "Our findings underline the importance of preventing childhood abuse and domestic violence. In addition, social workers and other health professionals must continue to support survivors of these childhood adversities across the lifespan, with particular attention to substance abuse and dependence issues."

Other significant predictors of both alcohol and drug dependence include lower levels of education, poverty, being male, being single as opposed to married, and a history of depression and/or anxiety disorders.