Several studies have demonstrated that the primary active constituent of cannabis, delta-9-tetrahydrocannabinol (∆9-THC), induces transient psychosis-like effects in healthy subjects similar to those observed in schizophrenia. However, the mechanisms underlying these effects are not clear.
A new study, published in the journal Biological Psychiatry, reports that ∆9-THC increases random neural activity, termed neural noise, in the brains of healthy human subjects. The findings suggest that increased neural noise may play a role in the psychosis-like effects of cannabis.
“At doses roughly equivalent to half or a single joint, ∆9-THC produced psychosis-like effects and increased neural noise in humans,” explained senior author Dr. Deepak Cyril D’Souza, a Professor of Psychiatry at Yale School of Medicine.
“The dose-dependent and strong positive relationship between these two findings suggest that the psychosis-like effects of cannabis may be related to neural noise which disrupts the brain’s normal information processing,” added first author Dr. Jose Cortes-Briones, a Postdoctoral Associate in Psychiatry at Yale School of Medicine.
The investigators studied the effects of ∆9-THC on electrical brain activity in 24 human subjects who participated in a three-day study during which they received two doses of intravenous ∆9-THC or placebo in a double-blind, randomized, cross-over, and counterbalanced design.
If confirmed, the link between neural noise and psychosis could shed light on the biology of some of the symptoms associated with schizophrenia.
“This interesting study suggests a commonality between the effects on the brain of the major active ingredient in marijuana and symptoms of schizophrenia,” stated Dr. John Krystal, Editor of Biological Psychiatry. “The…