Marijuana research

...A report released in October that analyzed 83 studies found marijuana is not effective for the treatment of depression or other mental illnesses. Many physicians say it increases the risk and severity of depression and thus the chances of suicide.

...Those sounding the alarm include the nation’s "mental health czar," as well as doctors in Colorado, California and Massachusetts where marijuana is legal for recreational use. They say the facts are irrefutable: Excessive use of high-THC pot and concentrated oil is linked to psychotic episodes that in some cases develop into full-blown schizophrenia.

...In May, more than 40 Massachusetts doctors, psychiatrists, pediatricians and other public health professionals urged the state to add psychiatric risk warnings to marijuana packaging and to prohibit most advertising.

The group cited research in The Lancet that found the use of high-THC marijuana increased risk of first-time psychosis by 50% in Amsterdam. Members said the more potent a drug, the higher the risk.

“Just as not all tobacco use causes cancer, not all marijuana/THC use causes the negative effects; however, the risk is substantial enough to require policies which discourage use,” the group's report said.

The state's Cannabis Control Commission rejected most of the health professionals’ recommendations.

"People say, 'This is only THC, and THC is harmless.’ That’s the assumption we all have to question," said Sharon Levy, a group member and pediatrician who heads the Adolescent Substance Use and Addiction Program at Boston Children's Hospital. "I don’t think it’s harmless at all."

She noted growers look to use the highest THC strains and companies make even higher-concentrated products, including gummy bears, oils and waxes, some with up to 90% THC.

“This is a business-driven framework, not a public health one,” Levy said. “There are very serious questions on this front.”

The psychotic side effects of marijuana are used to bolster arguments on both sides of the legalization debate. They find common ground in the need for more testing and studies.

Because marijuana remains a Schedule 1 controlled substance, the federal government strictly limits who can conduct research. Though Canada and Israel permit far more research access, approvals to study marijuana's benefits can take years in the USA where government-grown marijuana is tightly controlled.

Tests by marijuana legalization advocates found the federal government's testing supply can be 10%-15% weaker than cannabis sold in state-licensed dispensaries. In the past 20 years, average pot potency has tripled, from 4% THC in 1995 to 12% in 2014, according to federal testing.

It’s possible to buy a marijuana flower that’s more than 35% THC. Concentrates like those vaped by McIntosh can contain up to 90% THC.

Jim Carroll, director of the White House Office of National Drug Control Policy, said he talks to the Drug Enforcement Administration daily and pushes the agency and the FDA to "open up research" and make it possible for those who want to study medical uses of marijuana to obtain the type they want to study. The DEA announced plans to register more qualified marijuana growers for the research program, but Carroll told the USA TODAY editorial board this month legislation might be needed.

More research and stricter regulation would improve both the quality and the fact-based promotion of cannabis, said Scott Krakower, the assistant unit chief of psychiatry at Zucker Hillside Hospital in Queens, New York. The information would help legislators better determine if the benefits of legalization outweigh the risks.

He said many marijuana users are familiar with the possibility that smoking cannabis can cause paranoia, and paranoia is a textbook definition of an episode of psychosis, along with hallucinations and a distorted sense of reality.

"I think the biggest problem is that people think THC is a panacea cure for conditions, and they use an exorbitant amount of it" despite a lack of research to back that up, Krakower said.

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