Eight states and the District of Columbia have legalized cannabis use for recreational purposes, and 28 states plus the District of Columbia have legalized cannabis for medical purposes. Recent studies suggest that 45-80% of individuals who seek cannabis for medical purposes do so for pain management, and an estimated 6%-39% of patients prescribed opioid medication for pain are also utilizing cannabis. Over one-third of patients seeking cannabis for medical purposes list post-traumatic stress disorder (PTSD) as the primary reason for the request. Approximately 15% of Veterans who are treated in Department of Veterans Affairs (VA) outpatient PTSD clinics report recent (past 6 months) cannabis use.
Given the social, political, and legal changes surrounding cannabis use, physicians in both VA and non-VA settings will increasingly need to engage in evidence-informed discussions about the potential benefits and harms of cannabis use with their patients. Despite the rapidly moving legislative landscape, there is little comprehensive and critically appraised information available about what is known and not known about cannabis use for the treatment of chronic pain or PTSD.
The objectives of this systematic review are to: 1) assess the physical and mental health outcome effects of cannabis in patients with chronic pain; 2) assess the physical and mental health outcome effects of cannabis in patients with PTSD; 3) assess the impact of short- and long-term cannabis use on the risk of adverse effects such as pulmonary diseases, cardiovascular diseases, cancer, cannabis use disorder (CUD), and psychosis in the general adult population; and 4) provide a broad overview of more recently recognized "emerging harms" of cannabis use.
1. What are the effects of cannabis on health outcomes and healthcare utilization for adults who have chronic pain?
2. What are the effects of cannabis on health outcomes and healthcare utilization for adults who have PTSD?
3. What are the harms associated with cannabis use in adults?
4. What are important areas of ongoing research and current evidence gaps in research on cannabis for chronic pain or PTSD, and how could they be addressed by future research?
Nugent S, Morasco B, O'Neil M, et al. The Effects of Cannabis Among Adults with Chronic Pain and an Overview of General Harms: A Systematic Review. Annals of Internal Medicine. Published online on August 15, 2017. DOI: 10.7326/M17-0155.
O'Neil M, Nugent S, Morasco B, et al. Benefits and Harms of Plant-based Cannabis for Posttraumatic Stress Disorder: A Systematic Review. Annals of Internal Medicine. Published online on August 15, 2017. DOI: 10.7326/M17-0477.