Summary

background More and more adolescents with cannabis problems are seeking treatment at addiction clinics. There is an urgent need for new types of treatment in this field.
aim To evaluate the effectiveness of multidimensional family therapy (mdft) and cognitive behavioral therapy (cbt) in adolescents with a cannabis use disorder.
method One hundred and nine adolescents were randomly assigned to outpatient mdft or cbt. Both types of therapy groups had a planned treatment course lasting 5 to 6 months. After 12 months the two groups were compared in terms of changes in cannabis use and in terms of secondary outcome measures, including delinquency.
results Adolescents in both treatment groups showed significant and relevant reductions in cannabis use and delinquency over 12 months. Although the mdft treatment lasted longer and was more intensive than the cbt treatment, there was no difference in the key outcome measures of the treatments. Secondary analyses indicated that older adolescents and those without comorbid psychiatric problems derived considerably more benefit from cbt, whereas younger adolescents and those with comorbid psychiatric problems benefited much more from mdft.
conclusion mdft and cbt are equally effective in reducing cannabis use and delinquent behavior in adolescents with a cannabis use disorder. Age and comorbid psychiatric problems turned out to be important moderators of the treatment results of mdft and cbt and could therefore be used as a starting point for matching adolescent substance abusers to the most appropriate type of treatment.