A new report by the National Academies of Sciences, Engineering and Medicine shines a light on what the existing literature says about the perceived health benefits and dangers of using cannabis and cannabinoids.

“What little we know for certain about the effects of marijuana on human health — and all that we have reason to suspect — justifies serious national concern,” wrote the authors of the report, the evidence and research review of which was chaired by Marie McCormick, MD, of Harvard University in Boston. “The committee’s major recommendation called for an intensification and more comprehensive research effort into the effects of marijuana on the health of the American people.”

The authors concluded current literature shows substantial evidence stating that cannabis is effective at managing chronic pain in adults, while oral cannabinoid use is effective in mitigating nausea or vomiting induced by chemotherapy and improving patient-reported spasticity in patients with multiple sclerosis. Additionally, cannabinoids – specifically, nabiximols – are moderately effective in the short term for improving sleep disturbances brought on by obstructive sleep apnea syndrome, fibromyalgia, chronic pain, and multiple sclerosis.

However, there is limited evidence to support cannabis or cannabinoid use for reducing weight loss or inducing appetite in HIV/AIDS patients, improving clinician-measured spasicity or Tourette syndrome symptoms, reducing anxiety, improving symptoms brought on by post-traumatic stress, and improving outcomes in patients who have suffered traumatic brain injury or intracranial hemorrhage.

Additionally, there is no evidence to support the use of cannabis or cannabinoids in treating cancers or cancer-related anorexia, irritable bowel syndrome symptoms, epilepsy, spinal cord-related spasticity, symptoms of amyotrophic lateral sclerosis, Huntington’s disease, Parkinson’s disease, schizophrenia, and dystonia.

“Present data on drug use progression neither support nor refute the suggestion that medical availability would increase drug abuse,” the authors noted. “However, this question is beyond the issues normally considered for medical uses of drugs and should not be a factor in evaluating the therapeutic potential of marijuana or cannabinoids.”

From a mental health standpoint, suicidal thoughts were found to be more likely in individuals who frequently used cannabis or cannabinoids. Symptoms like depression and anxiety are also more likely in those who smoke marijuana and have bipolar disorder. There is also “limited evidence of a statistical association between sustained abstinence from cannabis use [and] impairments in the cognitive domains of learning, memory, and attention.”

Among the other significant findings of the report, children who live in states where marijuana has been legalized are significantly more likely to ingest cannabis or cannabinoids; so far, marijuana use in some form – either recreational or medical – has been approved in 28 states and Washington, DC. Furthermore, adolescents who use marijuana are more likely to experience difficulties in social and educational development. And individuals of any age who smoke marijuana and drive are more likely to be involved in a car accident.

Also noteworthy is the lack of evidence pointing to marijuana use causing cancer. While chronic marijuana smoking was found to be linked to bronchitis, it was not found to cause cancers that are most commonly associated with chronic smoking of tobacco.

“This report highlights that there are critical gaps in our understanding of the health effects of cannabis,” explained John H. Krystal, MD, of Yale University in New Haven, Connecticut.

A reviewer of the report, Dr. Krystal elaborated on the gaps that exist in the current literature, saying “One reason for these gaps has been regulatory and practical challenges facing those who attempted to conduct this research. For example, what supply of cannabis should they use? Where, in the typical hospital settings where research is conducted, should patients participating in research be permitted to smoke cannabis? What standards should the institutional review committees employ when evaluating studies that involve the administration of cannabis or other cannabinoids?”

Ultimately, Dr. Krystal stated, “what should be evident from this summary is that only a few of the many publicized clinical applications for cannabis are adequately supported by acceptable research standards for determining safety or efficacy.” Specifically, states that have approved cannabis use for managing PTSD symptoms are doing so based off “meager” evidence, and in some cases, are circumventing FDA regulatory processes in a way. This could not only compromise patient care, but muddy the waters for physicians who want to treat their patients safely while also following legal avenues.

“Physicians may face a tension between their roles as physicians [and] their wish to provide a legal path for access to cannabinoids for their patients,” Dr. Krystal said, adding that “the endorsement of particular cannabis prescription practices by the states, even for clinical indications where cannabis has not been shown to be safe and effective, may create pressure for physicians to engage in ineffective or unsafe cannabis prescription practices.”

Ultimately, the report underlines areas of need in terms of understanding and effectively using cannabis and cannabinoid in treating patients. Calling the report a “call to arms” for those in the health care – and, specifically, the public health – arena, Dr. Krystal added that he hopes the findings of the report will be used for educating “legislators, physicians, and consumers [about the] potential benefits and risks of cannabis and thereby help to guide both legislation, clinical practice, and perhaps recreational use.”

dchitnis@frontlinemedcom.com

New report highlights gaps in knowledge on marijuana use