Integrated Cognitive-Behavioral Therapy for Comorbid Cannabis Use and Anxiety Disorders: The Impact of Severity of Cannabis Use

Cannabis use disorder (CUD) is the most common illicit substance use disorder and individuals with CUD have high rates of comorbid anxiety disorders. Comorbidity between CUD and anxiety disorders is of public health relevance given that although motivation enhancement therapy (MET) combined with cognitive-behavioral therapy (CBT) is an efficacious intervention for CUD, outcomes are worse for patients with elevated anxiety. Integrated cannabis and anxiety reduction treatment (ICART) was developed based on translational research; it integrates a transdiagnostic CBT for anxiety disorders with MET/cognitive behavior therapy (MET-CBT) for CUD, with outcomes comparable to MET-CBT alone. The current study tested whether ICART is more efficacious than MET-CBT alone for patients with more severe baseline cannabis use and use-related problems. Individuals seeking treatment for CUD (56.4% male, M-age = 23.2, 63.3% non-Hispanic White) with at least one comorbid anxiety disorder were randomly assigned to ICART (n = 27) or MET-CBT (n = 28). Baseline severity of cannabis use and use-related problems moderated the relation between condition and posttreatment outcomes, such that among patients with the greatest baseline cannabis use, ICART was associated with less posttreatment cannabis use than MET-CBT alone. Further, among those with the greatest number of cannabis-related problems, patients in ICART reported fewer posttreatment problems than those in the MET-CBT alone condition. These data suggest that for dually diagnosed patients with more severe cannabis use, ICART may be more efficacious than a gold-standard psychosocial CUD treatment, MET-CBT. MET-CBT may be more efficacious for those with less baseline cannabis use.