A study of adults seeking treatment for anxiety and related disorders in Canada found that those who reported using cannabis more frequently had worse outcomes with cognitive behavioral therapy than those who used cannabis less or not at all. Despite this, cognitive behavioral therapy was quite effective in treating anxiety symptoms, even in the heavy cannabis user group. The study was published in the Journal of Psychiatric Research.
Cognitive behavioral therapy (or CBT) is currently recognized as one of the most effective methods of treating anxiety and a number of related disorders. These include trauma and stress-related disorders, obsessive-compulsive disorders, and others. Cognitive behavioral therapy works by teaching patients cognitive and behavioral skills to manage anxiety. These skills are practiced between therapy sessions.
People seeking treatment for anxiety often endorse the use of cannabis. Some of them may use cannabis to manage anxiety symptoms. However, cannabis use and anxiety can perpetuate each other. Individuals can use cannabis short-term to manage anxiety symptoms, but this can lead to later cannabis cravings that are associated with anxiety.
In their new study, Melise J. Ouellette and her colleagues wanted to investigate whether there was an association between the frequency with which patients undergoing cognitive-behavioral therapy for anxiety and related disorders use cannabis and the effectiveness of that therapy in reducing it the symptoms of the disorder. They were also interested to know if problems related to cannabis use were related to therapy outcome.
Participants were 253 adults seeking treatment for anxiety and related disorders with clinically significant symptoms of the disorders for which he/she was seeking treatment. Participants were asked to indicate how often they used cannabis. On this basis, they were divided into three groups – non-users (135 participants), light users (45 participants) and heavy users (73 participants).
Apart from that, they performed assessments of the severity of disruptions to daily living attributed to their illness, social anxiety, panic disorder symptoms, OCD symptoms, and PTSD symptoms.
The results showed that the severity of anxiety symptoms decreased in all groups during therapy. However, symptoms of anxiety disorder (or a related disorder) improved less over time in frequent cannabis users than in the non-user group.
There was no difference in the rate of symptom improvement during therapy between infrequent cannabis users and non-users, but also between frequent and infrequent users. In other words, the rate of improvement in infrequent users’ symptoms was between the rates of frequent users and non-users, but the difference between these rates was too small to be detectable with statistical analysis techniques employed by researchers.
When only cannabis users were considered, the severity of cannabis-related problems was not related to how rapidly the severity of anxiety symptoms changed during therapy.
“Frequency of cannabis use was associated with poorer outcomes of cognitive-behavioral therapy for anxiety and related disorders, but these individuals still achieved notable treatment success,” the researchers wrote. “Cannabis-related problems were not a significant predictor of cognitive behavioral therapy outcomes”
They added that “recent findings suggest that frequent cannabis use should not justify unilateral exclusion from cognitive behavioral therapy for anxiety and related disorders, since patients generally benefit from cognitive behavioral therapy despite their cannabis use.” In fact, successful cognitive behavioral therapy can have helpful downstream effects on cannabis use for those who use as a form of avoidance.”
The study is one of the first investigations into the relationship between cannabis use and the effects of psychotherapy. However, there are also limitations that must be considered. In particular, the study design does not allow any cause-effect conclusions about the relationships between the factors examined. In addition, cannabis use was assessed using self-report measures, and the categorization according to how often a person uses cannabis was not based on a standardized methodology.
The study ‘Does cannabis use affect outcomes of cognitive behavioral therapy in anxiety and related disorders? A Preliminary Investigation,” was authored by Melise J. Ouellette, Karen Rowa, Duncan H. Cameron, Ashleigh Elcock, Noam Soreni, Elizabeth J. Pawluk, and Randi E. McCabe.