“Smoking just one joint of marijuana is enough to trigger psychotic, depressive and anxiety symptoms in otherwise healthy people, British researchers report. The review of data involved 331 people with no prior history of psychotic or other major psychiatric disorders. It found that there’s enough THC (tetrahydrocannabinol)–the main psychoactive ingredient in pot–in one joint to cause serious psychiatric symptoms. ‘Our finding that THC can temporarily induce psychiatric symptoms in healthy volunteers highlights the risks associated with the use of THC-containing cannabis products,’ said study leader Oliver Howes, of King’s College London. Their conclusions were published March 17 in The Lancet Psychiatry and were based on data from 15 previously published studies. As Howes’ team pointed out, the link between marijuana and psychotic symptoms–such as hallucinations and paranoia–isn’t new. The first study to find such a connection was published more than 150 years ago. But the new review is one of the first systematic analyses of data collected since then. Symptoms such as depression, anxiety, apathy, delusions and hallucinations were included in the study. The study found an uptick in risk among marijuana users for all the psychiatric symptoms on their list. None of the findings came as a surprise to Dr. Scott Krakower, who specializes in substance abuse treatment for teens and young adults. Prior studies ‘have demonstrated that cannabis may be linked to future onset of psychotic and other mental health symptoms,’ said Krakower, who is assistant unit chief of psychiatry at Zucker Hillside Hospital in Glen Oaks, N.Y. He said the connection is especially strong for younger pot users, those who use the drug frequently, and people at genetic high risk for psychosis. ‘What is especially concerning are the psychotic symptoms, which are least transient in nature, and may be difficult to predict,’ Krakower said, and ‘patients may not realize that even a one-time use of marijuana may cause symptoms.’”
“One Joint,” UPI, Mar. 18, 2020