Cannabis Provides Sustained Relief for Depression

Patients suffering from treatment-resistant depression report sustained improvements in their health-related quality of life following the use of medical cannabis preparations, according to longitudinal data published in the Journal of Affective Disorders.

British investigators assessed the adjunctive use of cannabis-based medicinal products (CBMPs) in a cohort of 698 patients enrolled in the UK Medical Cannabis Registry. (British healthcare providers may prescribe cannabis-based medicinal products to patients unresponsive to conventional medications.) Patients’ outcomes were assessed at baseline and at 1, 3, 6, 12, 18 and 24 months. Study participants consumed either herbal cannabis or oil extracts containing standardized concentrations of THC and CBD.

Consistent with prior observational studies, participants reported “improvement[s] in mood, anxiety, general health-related quality of life, and sleep” over the duration of the study, with subjects reporting the most dramatic changes during the first three months. Few participants reported any serious adverse events. Patients who presented with the most severe depressive symptoms at baseline exhibited the greatest overall improvement in their symptoms.

The study’s authors concluded: “This UK Medical Cannabis Registry study of patients with treatment-resistant depression prescribed CBMPs demonstrated sustained and clinically meaningful improvements in depression, anxiety, health-related quality of life, and sleep quality over 24 months. Improvements were most pronounced within the first three months and were sustained thereafter. Adverse events were infrequent and predominantly mild to moderate. … Further randomized controlled trials, stratified by comorbidity profiles and product composition, are required to confirm efficacy, optimize treatment regimens, and clarify long-term safety.”