Study: Medical Cannabis Linked to Sustained Improvements in Depression, Anxiety and Sleep Over Two Years

OG article by Anthony Martinelli January 9, 2026

A recent study from the Journal of Affective Disorders highlights medical cannabis's potential for treating depression. Researchers from Imperial College London and Kings College London examined data from the UK Medical Cannabis Registry, focusing on 698 patients treated primarily for depression. Over 24 months, patients reported significant improvements in depression symptoms (measured by PHQ-9), anxiety (GAD-7), sleep quality (SQS), and overall quality of life (EQ-5D-5L). These benefits were most noticeable in the first three months, then stabilized. Notably, over half the patients had severe anxiety at baseline, showing high comorbidity with depression. Adverse events affected about 9% of participants, mostly mild issues like fatigue and insomnia. The observational study lacks a control group, so causality isn't proven, but results suggest cannabis-based products warrant further research, especially randomized trials, for real-world depression treatment. This adds to growing evidence on cannabinoids for mental health.