Study Suggests Even One Joint May Result In Temporary Psychiatric Symptoms

A new study published this week helps illuminate the psychiatric effects of cannabis. 

The research, which was published by The Lancet Psychiatry, found that “the acute administration of THC induces positive, negative, and other symptoms associated with schizophrenia and other mental disorders in healthy adults with large effect sizes.” As reported by CNN, the researchers concluded that “a single dose of the main psychoactive ingredient (THC) in cannabis — equal to one joint — in otherwise healthy people, can temporarily induce psychiatric symptoms, including those associated with schizophrenia.”

“The first takeaway is that for people in general there is a risk, even if you are healthy and taking a single dose, a one-off, you could have these symptoms,” said Oliver Howes, one of the study’s authors, as quoted by CNN. 

“They are distressing and could affect your thinking. You might not behave in a safe or rational way. It’s not just something that’s going to affect people with a history of mental health problems,” added Howes, who is a molecular psychiatry professor at King’s College London’s Institute of Psychiatry, Psychology & Neuroscience.

Howe and his colleagues researched 15 studies involving 331 “healthy” people who received both THC and placebo. He told CNN that they wanted to examine the effects of THC on otherwise healthy individuals who were not at risk of psychiatric problems. “This allows us to really test whether these cannabis components themselves lead to psychiatric symptoms,” Howe said.

More Cannabis Research Being Done

The study is part of what has become a flowering of academic research on marijuana in recent years that has dovetailed with governments and companies reconsidering longstanding prohibitions on pot. In October, researchers at the University of Georgia announced that they will study the effects of legalized medical cannabis on those suffering from chronic pain thanks to a multi-million dollar grant. Last April, the cannabis investor Charles R. Broderick made a $9 million donation that was split between Harvard and MIT to support research into how marijuana affects the brain and behavior. Broderick said the gift was driven by a desire “to fill the research void that currently exists in the science of cannabis.”