Expressive communicative ability, symptoms of mental illness and aggressive behavior.

The role of expressive communicative ability and level of mental illness symptoms in predicting aggressive behavior was explored in 67 adults with mental retardation. Overall rates of aggression were low with dangerous aggression more the exception than the rule. However, a subset of aggressive behaviors appeared to exist as a continuing risk for injury to others. Both expressive communicative ability and level of mental illness symptoms were strong predictors of aggressive behavior. In combination, high mental health symptoms and low expressive communicative ability were associated with the greatest prevalence of aggression.