Scientists are launching a new global study to see whether cannabidiol (CBD) can treat people with psychosis or psychotic symptoms.
CBD is currently only perscribed on the NHS for children and adults with rare, severe epilepsy and adults with vomiting or nausea caused by chemotherapy.
Oxford University’s department of psychiatry has been awarded £16.5m by charitable foundation Wellcome to launch a clinical trial later this year.
Entitled the Stratification and Treatment in Early Psychosis (Step) programme, it will be led by Professor Philip McGuire at Oxford and involve 1,000 people, including those at clinically high risk of psychosis, people with a first episode of psychosis and patients with psychosis who have not responded to conventional treatment.
The study will use Epidyolex, a form of CBD which is approved for some children and adults with epilepsy. Jazz Pharmaceuticals will supply the CBD for the study at no cost.
The programme will involve 35 centres, mainly in Europe and North America, and will be coordinated from Oxford.
CBD is a chemical found in marijuana, but it does not contain tetrahydrocannabinol (THC), the ingredient in marijuana which produces a feeling of being high.
Prof McGuire said the study will also investigate whether cannabidiol can prevent the onset of psychosis in people at high risk of developing it.
He continued: “Cannabidiol is one of the most promising new treatments for people with psychosis. Many people with psychosis are open to trying cannabidiol and previous smaller-scale studies have indicated that it has beneficial effects.
“This study could provide us with a new kind of treatment for psychosis and we are hugely grateful to Wellcome and Jazz Pharmaceuticals for helping to make it happen.”
Lynsey Bilsland, head of mental health translation at Wellcome, said: “This exciting programme will help us to find out if cannabidiol is effective at treating psychosis at various stages by testing it at scale.
“While antipsychotics are commonly used to treat psychosis, they can have significant side effects, patients often stop taking them, and they don’t work for everyone. This means that it is important that we explore avenues such as this one for new therapies.
“In addition, as part of these trials the researchers are aiming to identify biomarkers – biological signposts – which would indicate that a patient might respond well to the treatment. This will allow for greater personalisation of treatment in the future.”
A 2019 study found that CBD can counteract the effects of high strength “skunk” strains and may help to reduce the risk of serious mental health conditions like psychosis.
They found that strains with the same level of THC, but higher CBD caused less disruption to parts of the brain linked to addiction and psychosis.
