A study published in the Journal of Affective Disorders assessed medical cannabis effectiveness in managing severe depression for patients resistant to conventional pharmaceutical treatments. The goal of the study was to track longitudinal changes in patient-reported outcome measures (PROMs) documented in the Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), Single-Item Sleep Quality Scale (SQS), EuroQol 5-Dimension 5-Level (EQ-5D-5L), and Patient Global Impression of Change (PGIC) assessments completed by participants. Participants reported sustained improvements in their health-related quality of life following the use of medical cannabis products.
The researchers assessed the adjunctive use of cannabis-based medicinal products (CBMPs) in a cohort of 698 patients enrolled in the UK Medical Cannabis Registry. The study cohort mostly consisted of men (71.35%), and the mean age was 37 years. Study participants consumed either cannabis flower or oil extracts containing standardized concentrations of tetrahydrocannabinol (THC) and cannabidiol (CBD). The research team evaluated the patients’ outcomes at baseline and then again at 1, 3, 6, 12, 18, and 24 months.
The findings indicated that patients with treatment-resistant depression prescribed CBMPs experienced sustained and clinically meaningful improvements in depression, anxiety, health-related quality of life, and sleep quality over the two-year study period.
The participants noticed the most significant improvements within the first three months and sustained positive effects thereafter. Data analysis revealed that adverse events were infrequent and mostly mild to moderate reactions. Older patients and participants receiving higher CBD doses had a greater risk of experiencing an adverse event.
Current research on medical cannabis use for depression is limited. The research team recommended that additional randomized controlled trials, which include a more nuanced examination of comorbidity profiles and medical cannabis product composition, would increase efficacy and confirm long-term safety.
Sources: Journal of Affective Disorders, NORML, United Kingdom Medical Cannabis Registry