A NEW study involving clinicians in Musgrove Park Hospital, Taunton, has started to see if cannabidol (CBD) can reduce psychosis in patients with Parkinson’s.

The research and Parkinson’s teams of Somerset NHS Foundation Trust, which runs the hospital, have teamed up on a groundbreaking trial aiming to find out whether CBD is an effective treatment for patients with Parkinson’s disease, who also experience psychosis.

The CANnabidiol for Parkinson’s Disease Psychosis trial (CAN-PDP) is a clinical drug trial opened in some UK hospitals investigating whether CBD is a safe and tolerable treatment for reducing psychotic symptoms, such as hallucinations and delusions, in patients with Parkinson’s.

About three in five people with Parkinson’s experience symptoms, such as seeing, hearing, or feeling things that are not really there, which are hallucinations, or experience strange beliefs, which are known as delusions.

These symptoms are referred to as Parkinson’s disease psychosis (PDP).

Current treatment strategies are either not very effective, safe, or convenient for everyday use, which is why the trial is looking at CBD as a safer, more tolerable alternative.

CBD is a non-addictive chemical found naturally in the cannabis plant.

Research has shown CBD may safely and effectively reduce psychotic symptoms, but this has not been tested for psychosis specifically in Parkinson’s patients who are taking other medications.

The study team is also conducting a brain imaging sub-study to investigate changes occurring in patients experiencing psychosis during Parkinson’s, and whether CBD reduces these changes.

Foundation trust research nurse Nishi Singh said she was pleased the hospital was able to contribute to an important study which could have wide ranging implications for patients.

Ms Singh said: “The CAN-PDP study is aiming to recruit 120 patients across the UK.

“In Somerset, we have been set a target of two patients, and we have already reached this, although we are going to keep recruiting until the study closes.

“I think it is a really exciting study for our trust to be involved in and it could make a huge difference for patients with Parkinson’s who’re experiencing psychosis.

“We know not all patients with Parkinson’s have symptoms of psychosis, delusions, or hallucinations, but for those who do, it will be good to understand whether CBD can have a therapeutic effect in reducing those symptoms.”

Fellow research nurse Kimberley Gillman said: “Hallucinations can have quite an impact on the patient and those around them.

“It can be quite unsettling and scary for them when the people they love are experiencing psychosis.

“I am finding it exciting to be involved in this trial, as I have always found Parkinson’s a fascinating condition, and this could go on to change how we treat patients in the future.”

The trust’s principal investigator, consultant Dr Sarah Cleaver, said: “It is really exciting to be part of a national study looking to improve the quality of life of patients suffering with psychosis alongside their Parkinsons, as our current options for treatment are limited and psychosis can be so debilitating.”