Medical marijuana is legal in 29 states, but the amount of research that has been conducted related to the medical benefits of marijuana is still limited. That is because marijuana is still illegal at the federal level.

As a Schedule 1 drug, it is difficult, if not impossible, for scientists to get funding and the quantity, type, and quality of marijuana needed to conduct research. Therefore, when a new study is released, it’s big news, and a new report confirms that marijuana has proven benefits for multiple medical conditions.

The 378-page report from the National Academies of Sciences, Engineering, and Medicine, The Health Effects of Cannabis and Cannabinoids, gathers information from over 10,000 scientific studies and includes more than 100 conclusions from the authors. Among its conclusions, the authors identified a number of medical conditions for which marijuana has been scientifically proven as therapeutically effective.

Conditions were categorized based on whether there is conclusive or substantial evidence, moderate evidence, or limited evidence that cannabis and cannabinoids are therapeutically effective treatments.

Conclusive or Substantial Evidence of Effectiveness

According to the report, research provides conclusive or substantial evidence that cannabis or cannabinoids are effective for the treatment of chronic pain in adults. They are also effective as anti-emetics in the treatment of chemotherapy-induced nausea and vomiting, and for improving patient-reported multiple sclerosis spasticity symptoms.

Moderate Evidence of Effectiveness

There is moderate scientific evidence identified in the report that cannabis or cannabinoids are effective in improving short-term sleep in individuals who have sleep disturbances associated with obstructive sleep apnea syndrome, fibromyalgia, chronic pain, and multiple sclerosis.

Limited Evidence of Effectiveness

The report also cites studies where research has provided limited evidence that cannabis or cannabinoids are effective for increasing appetite and decreasing weight loss associated with HIV/AIDS, improving multiple sclerosis spasticity symptoms based on clinician measurements, improving Tourette syndrome symptoms, improving anxiety symptoms of people with social anxiety disorders, and improving post-traumatic stress disorder (PTSD) symptoms.

Matching Scientific Evidence with the Reality of Medical Marijuana

Unfortunately, scientific evidence doesn’t equate to patient access. Medical marijuana is only legal in 29 states, and despite the fact that science has proven conclusively or with substantial evidence that marijuana is an effective treatment for chronic pain, only 23 states include chronic pain as a qualifying condition to obtain medical marijuana.

Marijuana has also been proven conclusively or with substantial evidence to treat nausea related to chemotherapy and multiple-sclerosis spasticity symptoms. However, nausea is only approved for medical marijuana in 21 states, while multiple sclerosis is approved in 24 states.

There is moderate scientific evidence that marijuana is effective in improving sleep for individuals with sleep apnea, fibromyalgia, chronic pain, and multiple sclerosis. Despite the evidence, fibromyalgia only qualifies for medical marijuana treatment in Illinois, and sleep apnea is not approved in any states.

Furthermore, limited evidence shows that marijuana is effective in treating symptoms related to HIV/AIDS, multiple sclerosis spasticity, Tourette syndrome, anxiety, and PTSD. The good news is that 24 states have approved HIV/AIDS as a qualifying condition for medical marijuana, but only 15 have approved PTSD. Just two states have approved Tourette syndrome, and none have approved anxiety.

Bottom-line, science has spoken and laws need to catch up.