Cannabis ‘revolution’ requires closer look at its benefits, dangers

A “revolution” in legal access to cannabis over the past 20 years has raised concerns about its overuse, researchers wrote in a review published in Annals of Internal Medicine.

“Cannabis has some evidence for a few limited indications, but its widespread use is not consistent with these narrow indications,” Arthur Robin Williams, MD, MBE, an assistant professor of psychiatry at Columbia University, told Healio Primary Care. “Cannabis addiction is real, and there are real risks associated with its use, particular heavy daily use. It is also treatable and worth screening for.”

According to Williams and Kevin P. Hill, MD, MHS, an associate professor of psychiatry at Beth Israel Deaconess Medical Center, patients with cannabis use disorder often experience “great difficulty” reducing or stopping their cannabis use, which can lead to “addiction with compulsive, continued use and worsening consequences.” As many as seven million people in the United States meet the criteria for this condition each year, they wrote.

Williams discussed important takeaways from the review, which focuses on the effects of cannabis use, intoxication and withdrawal, as well as the causes of cannabis use disorder and evidence-based pharmacologic and psychosocial treatments.

Q: What does the latest evidence suggest about cannabis use for medical purposes?

A: The strongest evidence is consolidating around the use of cannabis for pain, especially neuropathic pain and spasticity. However, many states are permitting widespread advertising for indications, particularly psychiatric indications, for which there is no evidence of benefit.

Q: What strategies can primary care physicians use to identify patients with cannabis use disorder and those who are susceptible to cannabis poisonings?

A: Patients with a history of psychosis or paranoia should be incredibly careful when dosing cannabis, if not avoiding it entirely.

Q: What are the signs and treatments for acute cannabis intoxication?

A: Cannabis overdose is not lethal in its own right but can be incredibly debilitating. Sometimes patients have panic attacks, become frankly delusional and psychotic, and need to be hospitalized for a night or two. For some patients, the psychosis can persist for days or weeks after using, even a single use. While rare, overdose is a real risk and likely more common with naive users who start using edible products with much higher THC concentrations than they realize. Typically, patients only need supportive care, perhaps sedatives and anti‐anxiety mediations for the first day or two. We emphasized in the review article that patients are often unaware of how severe their addiction has become. Many of the symptoms reflect withdrawing from daily activities, relationships and work productivity.

Q: When should PCPs consult a specialist for treating patients with cannabis use disorder?

A: One key question that can indicate excessive use that is likely interfering with the patient's functioning and health is how early in the day they start using. If someone cannot get out of bed without using cannabis, that is usually a red flag.