Antisocial personality disorder (APD) is seen as one of the most impairing disorders during adulthood. In order to fill a gap on adolescent antecedents to APD, this study attempted to prospectively predict APD from psychopathology earlier in life in clinic referred samples of young adolescent males. This clinic-referred sample of 177 boys was recruited in 1987 from clinics in Pittsburgh, Pennsylvania, and in Athens and Atlanta, Georgia. Data used in this study were based on participants’ behavior between the ages of 13 and 19. The focus of the study was the development from adolescent conduct disorder (CD) to APD in young adulthood. Results indicated that out of the 158 cases with valid adolescent and adult data, 60 participants met the modified criteria for APD at either age 18 or 19. In addition, 94 participants met criteria for CD by combined parent-child report. The results clarify what the psychopathological characteristics are that distinguish those CD males who progress to APD and those who do not. Logistic regression analyses demonstrated that those CD cases which scored high on callous/unemotional behavior, depression, and use of marijuana were at highest risk to advance to modified APD. The results imply that in CD males, depressed mood and mood-altering drugs may further lead to disinhibition and lack of control of normal functioning associated with APD. Recommendations are discussed. References