Study suggests drug may reverse psychosis

Cannabis, a drug believed to increase the risk of psychosis in users, contains a compound that may be able to reverse psychotic behaviour, Monash researchers have found.

The scientists have identified a chemical compound in cannabis -- cannabidiol -- that has been found to reverse drug-induced behavioural disturbances in mice.

Leonora Long, a PhD researcher at the university's Victorian College of Pharmacy, said consumption of cannabis had been associated with an increased risk of developing psychosis because of the effects of tetrahydrocannabinol (THC), which creates the 'high' observed in humans.

"Our previous research has shown that cannabis compounds such as THC, that can produce psychosis in humans, also produce behavioural deficiencies in rodents that mimic symptoms of psychosis," Long said.

"Now, it has been shown in our animal tests that the cannabidiol compound reverses these types of behavioural deficiencies.

"This could mean that cannabidiol may reverse the symptoms of psychosis in humans," she said.

"The interesting thing is, that you have these two compounds in the cannabis plant that produce opposing effects. One is liable to produce psychotic symptoms, while the other may be protective against psychosis.

"Cannabidiol may also help alleviate the symptoms of epilepsy and also pain associated with inflammatory disorders such as Multiple Sclerosis," Long said.

The Monash researchers now plan to investigate the effects of cannabidiol and THC together in rats and mice, to see how the two compounds interact, and to mimic human consumption of cannabis.

Long, Dr David Taylor and Dr Dan Malone of the Department of Pharmaceutical Biology and Pharmacology, have published their findings in the journal Neuropsychopharmacology.

Monash University