How cannabis can help replace opioids to relieve pain and aid in addiction recovery
In of this series, we reviewed the current state of opioid addiction in the US, reflecting on how policy changes in pain management impacted opioid prescribing habits. Here, we evaluate evidence for using medical cannabis to treat chronic pain and help those addicted to opioids recover.
The idea of using cannabis to treat pain is not new – in fact, ancient Chinese civilizations used cannabis for joint pain and inflammation before it came to the West.  Opioids, derived from the poppy plant, have also been historically used for pain control; however, unlike cannabis, those who used opioids quickly learned of the risk of addiction. 
Cannabis shares some physiological similarities to opioids, as short-term use increases dopamine to relieve pain.  However, cannabis increases dopamine via cannabinoid receptors, while opioids increase it via opioid receptors.  Additionally, the increase in dopamine levels from cannabis does not persist over time and, therefore, the risk of possible dependence is significantly lower.
The effects of medical cannabis on pain have been demonstrated across many studies. A meta-analysis of 28 clinical trials conducted on cannabis and pain ranging from 1948 to 2015 reported positive findings, concluding that cannabis is effective in treating pain with a reasonable safety profile (side effects include memory and cognitive impairment that could impact driver safety, potential psychological and/or psychiatric effects, and other conditions related to consumption method, such as respiratory problems from smoking).  Medical cannabis has therefore been approved to treat chronic pain in the majority of states in the US where its use is legalized.
But, what about treating opioid addiction and not just pain?
States with legalized medical cannabis have significantly lower levels of opioid use and opioid-related deaths.  In addition, a study published in 2016 found a 64% reduction in opioid use in patients who also used medical cannabis for their chronic pain.  Pre-clinical and clinical studies have shown that CBD may be effective in reducing craving for opioids and easing withdrawal symptoms. 
Based on this evidence and the unrelenting opioid crisis, New Jersey and Pennsylvania have recently added opioid addiction as a qualifying condition for medical cannabis, and other states like New Mexico, Maryland, Connecticut, and Ohio are drafting similar policies. New York and Illinois likewise allow patients prescribed opioids to receive medical cannabis instead.
These policies certainly represent tremendous progress toward helping patients use medical cannabis to treat their pain and potentially aid them in recovery as they transition off of opioids. However, cannabis remains a Schedule I substance at the federal level, which restricts patients’ access to it and continues to slow critical research. Despite growing awareness and recognition of the potential for medical cannabis in alleviating the epidemic caused by opioid addiction, we firmly believe that ending prohibition entirely is the only way to further progress and alleviate this crisis in the United States.
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