A global study is to be launched which aims to investigate if a non-psychoactive component of the cannabis plant, cannabidiol (CBD), can be used in the treatment of psychosis.

The first-of-its-kind study, being led by scientists from Oxford University, will not only investigate CBD as a treatment for psychosis and psychotic symptoms but also as a preventative medicine to be prescribed to people at high risk of psychosis. 

Headed by Professor Phillip McGuire, and supported by colleagues at King’s College London, the study, named the Stratification and Treatment in Early Psychosis (STEP) programme, will be conducted over 38 sites in 11 countries, and involve three clinical trials and 1000 participants. 

CBD has been touted by many as a wonder drug that works for many illnesses, conditions and ailments. It can come in many different ways, oils, gummies, chocolates, coffee and even in pillows!

In recent years, CBD has become notorious as a cure-all for many illnesses, conditions and ailments. While some claims remain unsubstantiated, clinical research as well as anecdotal and real-world evidence suggests that CBD, both with and without THC and other cannabinoids, can be beneficial for a broad range of conditions. 

Scientists are still unclear about how CBD and cannabis in general work, although it is widely agreed that it modulates our endocannabinoid system (ECS) after binding with the cannabinoid receptors that we have in places such as the brain and liver. 

The science behind the ECS, as with all cannabis and psychedelic science, is still in its infancy. The ECS was only discovered in 1984 and its role in the body is not fully understood. However, it is believed to regulate the immune and central nervous systems, as well as performing other tasks such as the modulation of neurotransmitters, metabolism and inflammation.

Speaking to the Guardian, Prof McGuire said, “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.”

There is mounting evidence that CBD can be beneficial for those with psychosis and psychotic symptoms by regulating the dopamine system, much like traditional antipsychotic drugs. 

Cannabis has been legal to be prescribed in the UK since 2018. CBD, when prescribed as a medicine is licensed, but only for a handful of conditions, such as rare and severe types of children’s epilepsy, and for the treatment of nausea and vomiting in patients having chemotherapy. 

The CBD that will be administered to participants in the large study coordinated by Oxford University will be supplied for free by Jazz Pharmaceuticals, and will be one of their licensed products already in use to treat severe epilepsy. 

It is thought that by using an already licensed product the team of scientists working on the trial will be able to more easily and accurately regulate, monitor and view the impact of specific doses of CBD given to participants. This is considered important as it should be easier to translate the trial results into a product that works in clinical practice. 

What is psychosis?

Psychosis is characterised as disruptions to a person’s thoughts and perceptions that make it hard for the person to tell the difference between what is real and what is not. This can manifest in the person seeing, hearing or imagining things or situations that don’t exist, or displaying strange behaviours. As many as 1 in 30 people may experience psychotic symptoms at some point in their life. 

Psychosis can be very frightening and disorientating to those suffering from it, and to others who live with or are close to somebody having a psychotic experience. It is not considered to be an illness, but a symptom.

Traditional drugs used to treat psychosis such as quetiapine and olanzapine work by blocking dopamine receptors in the brain. They have been used with a lot of success since the 1950s. Despite their success in the revolution of psychosis treatments, they can produce severe side-effects, and don’t work for everybody.  

Cannabis causes psychosis, doesn’t it?

Cannabis has been blamed for causing psychotic disorders for decades, Reefer Madness was a public service movie produced by the US Government in 1936 that portrayed a group of college students who after trying marijuana for the first time deteriorated into addiction, crime and madness. 

The aim of the film was to persuade the youth of America that cannabis causes madness and leads to a life of crime. Today it is viewed as the incredibly inaccurate propaganda film that it was, and thankfully science is more respected now when it comes to cannabis.  

There have been many studies investigating cannabis as being the cause of psychosis and psychotic symptoms, with different conclusions being drawn over the years. 

However, the general consensus now is that it isn’t seen to be a driving factor. A study from 2021 investigated if exposure to cannabis during adolescence caused psychosis by studying sets of twins. It found no evidence to support the theory that cannabis causes psychosis through early years exposure.  

STEP Programme 

Scientists working on the programme will use neuroimaging techniques such as MRI and spectroscopy before and after treatment of the 1000 participants to thoroughly investigate the effects CBD has on the body and brain. 

Researchers will also assess variants such as blood, cognition and other clinical measures to identify biomarkers that might predict if a patient responds favourably to CBD treatment. The study was supported by a £16.3 million grant by the charitable foundation Wellcome Trust. Wellcome Trust provides capital for research that it thinks “improves health for everyone by funding research, leading policy and advocacy campaigns, and building global partnerships.”