Cannabis extract may offer treatment for psychosis

A single dose of the non-intoxicating compound of cannabis -- cannabidiol -- can help reduce brain function abnormalities seen in people with psychosis, results of a clinical trial, led by an Indian-origin doctor, has revealed.

Psychosis is a mental disorder characterised by a disconnection from reality.

Brain activity in the people at risk of psychosis remains abnormal compared to the healthy ones. 

But in people who had cannabidiol, the abnormal brain activity was less severe than for those who received a placebo, suggesting cannabidiol can help re-adjust brain activity to normal levels.

The results suggest that cannabidiol may normalise dysfunction in striatum, parahippocampal cortex, and midbrain -- brain regions which are critically implicated in psychosis -- and this may underlie its therapeutic effects in psychosis, the researchers explained.

"Our results have started unravelling the brain mechanisms of a new drug that works in a completely different way to traditional anti-psychotics," said Sagnik Bhattacharyya from Britain's King's College, London. 

For the study, published in JAMA Psychiatry, the team studied a small group of young people who had not yet been diagnosed with psychosis but who were experiencing distressing psychotic symptoms, along with healthy controls. 

All participants were studied in an MRI scanner while performing a memory task which engages three regions of the brain known to be involved in psychosis.

"One of the main advantages of cannabidiol is that it is safe and seems to be very well tolerated, making it, in some ways, an ideal treatment," Bhattacharyya said. 

"If successful, this trial will provide definitive proof of cannabidiol's role as an antipsychotic treatment and pave the way for use in clinic," he noted.