Neurobehavior disinhibition in childhood predicts suicide potential and substance use disorder by young adulthood

The objectives of this study were to (a) determine whether two factors that are established components of the risk for substance use disorder (SUD) also impact on the risk for suicide; and (2) evaluate whether SUD manifest by early adulthood predicts suicide propensity. Neurobehavior disinhibition assessed in 227 boys at ages 10-12 and 16 and parental history of SUD were prospectively evaluated to determine their association with the risk for SUD and suicide propensity between ages 16 and 19. The results indicated that neurobehavior disinhibition at age 16 predicts suicide propensity between ages 16 and 19 (p =.04). A trend was observed (p =.08) for SUD manifest between ages 16 and 19 to predict suicide propensity during the same period. Maternal SUD is directly associated with son's SUD risk but not suicide propensity. Paternal SUD predicts son's neurobehavior disinhibition that, in turn, predisposes to SUD. A direct relation between paternal SUD and son's suicide propensity was not observed. These findings suggest that neurobehavior disinhibition, a component of the liability of SUD, is also associated with suicide risk. These results are discussed within a neurobehavioral framework in which prefrontal cortex dysfunction is hypothesized to underlie the risk for these two outcomes. (C) 2004 Elsevier Ireland Ltd. All rights reserved.