This report, carried out by the Policy Research Bureau of the Home Office, deals largely with antisocial behavior in adolescence and its potential trajectory into adult antisocial personality disorder (ASPD). Adults with ASPD represent a potentially dangerous group, but are few in number. This report reviews the available literature in order to answer the questions: (1) what is antisocial personality disorder; (2) what is known about the developmental pathways and risk factors leading to the disorder; (3) is it possible to identify adolescents at high risk of ASPD in adulthood; (4) what interventions with adolescents are successful in preventing the progression of ASPD in adulthood; and (5) what are the implications of these findings for future research, policy, and service provision? The literature review searched for information regarding risk factors for severe personality disorder and interventions with adolescents. The report is divided into five major areas: (1) definitions in the field of antisocial behavior; (2) the main risk factors identified as predictive of ASPD; (3) considerations in designing and evaluating interventions for high-risk adolescents; (4) identifying high-risk adolescents; and (5) research on interventions with adolescents and their outcomes. A review of the evidence suggests that there is limited knowledge of the risk factors that lead to ASPD and an even more limited knowledge of the best means of identifying high-risk adolescents on a trajectory into ASPD. There are significant gaps in the knowledge concerning interventions that work for adolescents in preventing severe antisocial personality disorder. Much more research needs to be undertaken to establish conclusive evidence of the power of interventions to alter the trajectory of very high-risk groups. References