Testing Psychedelics Efficacy On 'Psychiatry's Blind Spot': Latest King's College Trial

A new open-label study Sponsored by King’s College London (KCL) will assess the effects of a single psilocybin dose of 25 milligram on subjects with a diagnosis of the common and disabling Functional Neurological Disorder (FND).

The National Institutes of Health (NIH) defines this condition as “a group of common neurological movement disorders caused by an abnormality in how the brain functions” with two primary categories: psychogenic nonepileptic seizures, and functional movement disorder.

There are many types of FND, with a diverse mix and range of neurologic symptoms and disorders. For some people, symptoms are short-lived, while they may last for years for others.

Austrian neurologist Sigmund Freud named it “conversion disorder” because he believed it was originally a psychological disorder turned into a neurological one.

Although FND’s exact cause is unknown, it sometimes has a psychological cause as one of the relevant factors and may result from a somatic symptoms disorder, commonly associated with distress or dysfunction and looking like a physical illness.

The disorder is found particularly in those who have a history of early life trauma.

While FND gives the brain no significant structural damage, it makes it momentarily unable to function normally: it cannot send and receive signals properly, thus affecting the function of the lobes, emotional processing and potentially memory, concentration, cognition and the processing of sensations. 

That is, FND “causes real symptoms that significantly interfere with how you function and cope with daily life,” as stated by the NIH. Unplanned movements and symptoms occur without the person consciously starting them, can involve any body part, and may appear suddenly, increasing with attention to them and decreasing when distracted.

KCL’s trial takes base from an institutional 2020 systematic review which concluded that “there are encouraging lessons to learn from preprohibition studies of adjunctive psychedelic therapy in functional neurological disorder” and that “further investigations of feasibility and safety of treatment with psychedelics (more specifically, psilocybin) in patients with functional neurological disorders is a potential future research option.”

The present study’s leading question is: “Can the default mode network, a brain network thought to be relevant in FND, be modified by the administration of psilocybin based on functional magnetic resonance imaging before and after the dose?”

For that aim, it will assess how the brain’s default mode network of subjects suffering from FND responds to psilocybin with support psychotherapy via functional Magnetic Resonance Imaging (fMRI), measuring a change in functional brain connectivity one week prior to dosing versus one-week post-dosing.

The trial’s start date is estimated in August 2023, recruiting approx. 24 subjects aged between 25 and 60 years holding moderate to severe symptoms that have been present for over 12 months and have failed to respond to best available treatment (including cognitive behavioral therapy and physiotherapy.)

This study’s exclusionary criteria are subjects with diagnoses of severe depression, bipolar affective disorder, psychotic disorders, drug or alcohol dependence disorders, personality disorders, dementia, autistic spectrum disorder, learning disabilities, significant suicidal behavior (as defined by C-SSRS), pregnant or breast-feeding women and, importantly, those who have used psychedelic substances more than two times in the past year.

Photo: Benzinga edit with photo by Wikimedia Commons.