To examine the post-treatment effectiveness of an outpatient, individual social skills training for juvenile
delinquents in the Netherlands and to conduct moderator tests for age, gender, ethnicity, and risk of reoffending.
sample consisted of juveniles who received Tools4U, a social skills training with a parental component, as a penal sanction
(N = 115). Propensity score matching was used to select a control group of juveniles receiving treatment as usual (TAU) of
n = 108 juveniles (of a total of N = 354). Assessment of impulsivity, social perspective-taking, social problem-solving, critical
reasoning, developmental task-related skills, and treatment integrity took place before and immediately after the treatment.
integrity was found to be sufficient, so that treatment effects could be attributed to the Tools4U training. Tools4U was more
effective than TAU in reducing impulsivity, cognitive distortions (self-centering and assuming the worst), and social perspective-taking
deficits (hostile intent attribution). No treatment effects were found on adolescents’ social problem-solving skills, and
only caretakers of girls showed improvement in parenting skills. Effects on developmental task-related skills were not in
the expected direction: after Tools4U, juveniles reported significantly less social acceptance and self-worth than juveniles
Tools4U showed generally small effects and no effects on protective factors, which
might limit the long-term treatment effects on delinquency. Treatment effects may be improved by implementing additional techniques
and improving the parental component for boys in particular.