Major trials to test effectiveness of cannabidiol on psychosis
Thursday 16th Feb 2023, 3.33pm
Wellcome has awarded Oxford’s Department of Psychiatry £16.5 million for the STEP (Stratification & Treatment in Early Psychosis) programme, as part of its support for mental health research.
The programme, led by Professor Philip McGuire, Professor of Psychiatry at Oxford, will involve 1,000 participants, including people at a clinically high risk for psychosis, people with first episode psychosis, and people with psychosis who have not responded to conventional treatment.
The programme involves 35 centres, mainly in Europe and North America, and will be co-ordinated from Oxford at the Prince of Wales International Centre for SANE Research.
Jazz Pharmaceuticals has supplied the cannabidiol for the trials at no cost.
Professor McGuire said: ‘Cannabidiol is one of the most promising new treatments for people with psychosis. This study will be the first to evaluate cannabidiol in large numbers of people with psychosis or psychotic symptoms, and brings together many of the leading centres working in this area around the world.
‘Many people with psychosis are open to trying cannabidiol and previous smaller scale studies have indicated that it has beneficial effects. As well as treating psychosis that is already established, the study will also investigate whether cannabidiol can prevent the onset of psychosis in people at high risk of developing it.
‘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.’
The cannabidiol used in the study is extracted from the cannabis plant. The medication is more than 99 per cent cannabidiol. Other constituents of cannabis, which could have adverse psychoactive effects, have been removed. The form of cannabidiol that is being used in the study is the same as the only licensed form of cannabidiol (known as Epidyolex), which has been approved for use to treat seizures for some conditions in children.
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.’
Participants will be assessed before and after treatment using a range of clinical, digital, cognitive, neuroimaging and blood measures to clarify how cannabidiol acts to produce its effects and to identify factors that predict the response to treatment.
In order to correctly measure the effect of cannabidiol, half of the participants will be treated with placebo and the other half will receive cannabidiol. Cannabidiol or placebo will be administered alongside the standard medical treatments for psychosis.
The Prince of Wales International Centre for SANE Research, the hub of this research, was opened 20 years ago this month by the now King Charles III.
Marjorie Wallace CBE, founder and Chief Executive of mental health charity SANE, said: ‘We built the Centre as a flagship of hope for researchers, patients and their families to discover new and more effective treatments and to disseminate information and research into severe mental illness. We are delighted to work with Professor McGuire’s team in this exciting and potentially breakthrough trial.’
