Victimization History and Aggressive Behavior Among Adults with Intellectual Disabilities: The Mediating Role of Mental Health

Over the past few decades, considerable research has focused on the risk and protective factors associated with aggressive behavior among adults with intellectual disability (ID). The primary objective of this study was to examine the factors underlying the association between victimization history (sexual or physical) and risk for aggressive behavior among adults with ID. To do so, 215 adults with mild or moderate ID living in the community and receiving services from specialized ID agencies were recruited. Through interviews, primary case managers completed measures assessing aggressive behavior and potential mental health problems. Victimization history was assessed through a review of participants' charts and interviews with the primary case manager. Consistent with previous research, we found a significant association between victimization history and aggressive behavior. Mental health problems mediated this association. More specifically, results showed that symptoms of psychosis and personality disorders, but not symptoms of depression, mediated the association between victimization history and outward aggressive behavior. The discussion addresses cognitive and emotional factors that might contribute to the association between victimization history, mental health problems and aggressive behavior among adults with ID. Clinical implications are also discussed.