Predictors of Effective Therapy among Individuals with Cannabis Use Disorder

Background: Treatment demand for Cannabis Use Disorder (CUD) has increased in the past decade in almost all European countries, and CUD is currently the most common reason for first-time drug-related treatment admission in the European Union. Even though several therapeutic approaches have been shown to benefit individuals with CUD, there is a lack of knowledge regarding factors associated with effective therapy and the underlying mechanisms of change among individuals with CUD presenting for treatment. The aim of the present paper was to review current knowledge on factors that have been shown to contribute to positive outcomes in CUD treatment, focusing on empirically evaluated studies that used defined, cannabis-related outcome measures.
Methods: A scoping review of qualitative studies was conducted. Studies were included if they specifically assessed treatment outcome among patients with cannabis-related problems. Studies which did not distinguish cannabis-related problems from other SUDs, those which did not define clear treatment outcome measures and studies focusing on medicinal cannabis were excluded. In addition, we excluded studies focusing on the effectiveness of public-health campaigns and harm-reduction strategies (e.g., cannabis products labeling, etc.), which do not fall under the conventional definition of therapy.
Results: Findings suggest two sets of factors that contribute to positive treatment outcome. Moderating factors are patient-related characteristics that predict his/her odds to benefit from treatment. In CUD treatment, these include sex, ethnicity, age-related factors and comorbid disorders. Treatment mediators are treatment-related factors associated with the processes or mechanisms through which patients benefit from therapy. In CUD treatment, these include specific factors, i.e.., therapeutic ingredients which are thought to promote change in psychotherapy, such as addressing motivation to change, acquiring coping skills, enhancing self-efficacy, and integrating several therapeutic components. Another type of mediators is common factors, which are therapeutic mechanisms that influence therapeutic outcomes to the same extent across all treatment modalities. In CUD treatment, these include therapeutic alliance, empathy and cultural adaptation.
Conclusions: Further research is needed to identify unique facilitators and barriers to successful treatment of CUD.