Medical cannabis improved pain, quality of life, and reduced opioid use over 12 months in 751 patients

Among 751 chronic pain patients initiating medical cannabis treatment, pain severity and interference improved significantly at 1 month and remained improved through 12 months (p<0.001). Physical and mental health domains improved starting at 3 months (p<0.002). Headaches, fatigue, anxiety, and nausea all decreased significantly (p≤0.002). Among opioid users at baseline, oral morphine equivalent doses decreased significantly (p<0.0001).

Prospective, 12-month observational study at a medical cannabis clinic (October 2015-March 2019). Patients completed the Brief Pain Inventory, SF-12, and opioid use surveys monthly for 12 months.

This is one of the larger and longer prospective studies of medical cannabis for chronic pain. The sustained 12-month improvement and opioid dose reduction address two critical clinical questions: does it keep working, and does it reduce reliance on opioids?

The combination of sustained pain relief, improved quality of life, and reduced opioid use over a full year supports medical cannabis as a practical treatment option, not just a short-term novelty effect.

No control group (observational); self-selected patients at a cannabis specialty clinic; potential for placebo and expectancy effects; attrition over 12 months not detailed; cannot determine which cannabis products or doses were most effective.