The results affirm the importance of directly targeting parental sense of competence and positive discipline in future interventions aimed at decreasing adolescent problem behavior.

These findings point out the clinical relevance of adequately assessing psychopathic traits in adolescents referred for treatment of antisocial behaviour, and identifying those adolescents who show high levels of these traits. It is important to tailor MST specifically to meet the needs of juveniles with high levels of callous/unemotional traits and high levels of narcissism to obtain the same level of effectiveness as with juveniles scoring lower on these traits.

Objective In the present randomized controlled trial, the effectiveness of multisystemic therapy (MST) in The Netherlands was examined. Moderator tests were conducted for ethnicity, age and gender. Methods The sample consisted of N0256 adolescents, referred because of conduct problems, and randomized to MST or treatment as usual (TAU). Assessments (questionnaires and observational ratings) took place before and immediately after the treatment. Results MST was more effective than TAU in decreasing externalizing behavior, ODD, CD and property offences, but not for violence. Findings were mixed for adolescents' and parental cognitions: the MST group, compared to TAU, showed an improvement in parental sense of competence, and a decrease in adolescents' hostility, but no change in self-esteem and an increase in personal failure. MST was effective for positive dimensions of parenting and associations with prosocial peers, but not for relationships with deviant peers. MST was equally effective for adolescents of different ages and with different ethnicities. However, MST showed larger (and more positive) effects for adolescent cognitions for boys than for girls.

The relationship between adolescent personality and problem behaviour has been well established. However, relatively little attention has been given to the role of the social environment in the association between adolescent personality and problem behaviour. We tested the mediating and moderating role of the quality of the parent-adolescent relationship in the associations between adolescents' personality traits and problem behaviour. The sample consisted of 140 adolescents (11 to 18 years of age) and both their parents. Results supported a mediating role of the father/mother-adolescent relationship in the associations between Agreeableness, Emotional Stability, and Conscientiousness and externalizing problem behaviour. The father/mother-adolescent relationships did not mediate the associations between personality traits and internalizing problem behaviour. We also found support for a moderating role of the father/mother-adolescent relationships in the association between Emotional Stability and both externalizing and internalizing problem behaviours. Other moderated effects were specific for parent, personality trait and type of problem behaviour.