Panelists urge caution in using cannabis for psychiatric conditions

NEW ORLEANS – Evidence on the use of cannabis for medical conditions is limited, so clinicians should be cautious when discussing it with patients, Kevin P. Hill, MD, MHS, said at the American Psychiatric Association annual meeting.

Hill, director of the division of addiction psychiatry and associate professor of psychiatry at Beth Israel Deaconess Medical Center/Harvard Medical School, participated in a panel discussion on medical marijuana.

“We’re in a critical period,” he said. “There is some evidence supporting the use of cannabinoids for medical indications. For psychiatry conditions, evidence is very scant, and there are considerable potential risks.

“While it would be great to have additional research in this area,” Hill continued, “it’s important to be clear in your office with patients about where the evidence stands now. It’s very limited at this point. There would be rare cases where cannabinoids would be viable treatments for psychiatric patients.”

Panelist Deepak Cyril D'Souza, MD, MBBS, said his research has shown that THC exacerbated positive and negative symptoms in patients with schizophrenia.

“Relative to healthy controls, patients with schizophrenia were much more vulnerable to changes,” said D’Souza, professor of psychiatry and director of the Schizophrenia Neuropharmacology Research Group at Yale; director of the Neurobiological Studies Unit, VACHS; and director of the VA-CMHC Schizophrenia Research Clinic.

“THC impaired memory in healthy individuals, but it impaired it in patients with schizophrenia more,” he said.

D’Souza noted that the positive and negative effects may be dose-related.

“Participants are randomly asked at various times of the day to report on psychosis symptoms,” he continued. “Was it the case that after using the cannabis, the symptoms got better or worse? Or did an increase in symptoms drive the use of cannabis?

“At the present time, the risks of cannabis far outweigh the benefits,” he concluded.

D’Souza noted that the Veterans Administration is planning a study to evaluate CBD and THC for pain management.

The panelists also discussed cannabis policy in the U.S.

“Implementation of medical cannabis policies have not gone well,” Hill said. “Those who support it say the access is not what it should be. Others say policies are not stringent enough.

Millions of people are using cannabis and cannabinoids, he said. Thirty-seven states and the District of Columbia have policies in place for medical cannabis.

“Many of the states point to a core group of about 15 or so qualifying conditions, but, overall, there’s a lot of variability,” Hill said. “In those 37 states, the number of conditions varies from five to 29.

“Anxiety is one of the top conditions,” he continued. “There’s a lot of anecdotal evidence. There are 31 studies, 17 randomized clinical trials. No studies have evaluated medical cannabis specifically as a treatment for anxiety disorders. It’s used a lot for posttraumatic stress disorder, but the level of evidence is not there.

“Depression is similar,” Hill said. “No studies are pharmacological studies looking at depression primarily. None of them showed efficacy. Some showed that it worsens depression.”

He added that no medical cannabis trials evaluated smoked cannabis.

“The science is building, but the policies are not tied very well into the science at this point,” Hill said.

“People say cannabis is safer than alcohol,” panelist Kevin Sabet, PhD, assistant professor adjunct at Yale School of Medicine, Institution for Social and Policy Studies, said. “Alcohol has been in our culture since before the Old Testament. Cannabis has been part of the counterculture. We should not base cannabis policy on alcohol policy.

“Alcohol has been commercialized, and it’s a major source of health problems and criminal problems,” he continued. “It’s a multibillion-dollar industry whose business it is to get people to use more.”

Sabet said use of cannabis should be delayed as long as possible because of the high potency products available.

“Companies and states are making money off of this, but they are not advancing the science like they should,” Hill said. “If you think about the amount of money that states and companies are making, it’s embarrassing that we don’t know more. How about the efficacy for treating pain? We’re not doing enough rigorous randomized clinical trials.”

“Maybe they’re not funding it because they’re afraid of what they’re going to find,” Sabet responded. “The issue of scheduling is fascinating. Everywhere I go, people say marijuana is a Schedule I drug. I was at the White House in the past, and someone asked me why we treat heroin, also Schedule I, like marijuana. It clicked that even that policy person thought that because two different drugs are on the same schedule we treat them the same way. It’s not an index of harm.”