Childhood adversity is acknowledged to be a predictor of adolescent and adult antisocial behavior and substance abuse (Dodge et al, 1990; Verona and Sachs-Ericsson, 2005). Animal studies of maternal deprivation and abuse suggest that the effects of adversity are likely to be greatest if they are experienced early in life and are also likely to be persistent (Liu et al, 1997; Maestripieri et al, 2005). Likewise, studies in children have shown that maltreatment prior to age five has the greatest impact (Keiley et al, 2001).
