University of Florida
Objective: In response to the need of more rigorous data on marijuana use and chronic pain, we conducted a 12-month prospective study to examine the effects of medical marijuana on pain, opioid use, anxiety/depression, and quality of life.
Methods: Fifty-six adults (age=54.8±11.9, 53.6% male) were recruited from medical marijuana clinics before initiating medical marijuana treatment. Participants completed surveys on various clinical outcomes at baseline (i.e., 2-3 weeks before they started medical marijuana use), 3 months, and 12 months.
Results: At baseline, the mean of worst and average pain of the group was 8.0±1.6 and 5.9±2.0 respectively, on the scale from 0 to 10, indicating chronic pain. At 3 months (retention rate=93.9%), the proportion of individuals reporting “no more than minor pain in past 24 hours” increased from 12.7% at baseline to 32.6%. The proportion of daily opioid users decreased from 53.6% at baseline to 28.6%. Participants also reported significantly lower levels of worst pain (7.2 vs. 8.0, t=-2.25, p<.05), average pain (5.1 vs 5.9, t=-2.62, p<.05), pain interference (2.8 vs. 3.6, t=-4.12, p<.001), and depression (5.6 vs.8.1, t=-3.64, p<.001), as well as increased hours of sleep (6.1 vs. 5.4, t=4.02, p<.001), sleep quality (1.7 vs. 1.2, t=2.96, p<.01), and quality of life (3.3 vs. 2.8, t=5.01, p<.001), compared to baseline. At 12-months (retention rate=76.0%), 73.7% of the participants were still using medical marijuana. Among these continuous users, 78.6% thought medical marijuana was moderately to extremely effective for their chronic pain; 78.6% were able to reduce or totally quit opioids; 81.4% reported better physical functioning; 78.6% reported better mental health; 85.7% reported better sleep quality; and 85.7% reported better quality of life. On the other hand, 35.7% said they needed a higher dose of medical marijuana now to achieve the same effect; 42.9% reported experiencing some side effects (e.g., blurred vision, dry mouth, paranoia); and 21.4% reported worse cognitive abilities due to medical marijuana use.
Conclusions: In our sample of primarily middle-aged and older adults with chronic pain, medical marijuana was associated with improved health (e.g., reduced pain, improved sleep) as well as adverse (e.g., side effects, cognitive impairment) outcomes.
Co-authors: Jennifer Jean Jacques1, Zhigang Li1, Kimberly Sibille1, John Crump2, Barbara Aggarwal3, Robert Cook1
1University of Florida, 2 Releafe Now clinic, 3 CannaMD clinic