Psilocybin-Assisted Therapy in Functional Neurological Disorder

Professor Richard Kanaan's team at Austin Health are leading an exciting clinical trial investigating psilocybin-assisted physiotherapy in refractory motor functional neurological disorder (FND).

Motor FND presents with motor neurological symptoms - such as weakness, tremor, and abnormal gait - which are considered incompatible with organic neurological disease. It is a common and disabling illness, with few available treatments, including no direct pharmacological treatments. Expert consensus recommends physiotherapy as part of a multidisciplinary approach. However, despite encouraging outcomes from several studies for physical rehabilitation in motor FND, many individuals continue to experience persisting, disabling symptoms. There exists a theoretical basis that physiotherapy for motor FND may be augmented by psilocybin through modifying altered brain signalling processes and allowing individuals to relearn normal behaviours during motor retraining.

However, no studies have investigated psychedelics combined with physiotherapy, let alone the impacts of psychedelics on motor function in healthy or clinical populations. We therefore initially completed a dose-finding pilot study of undertaking movement tasks during the acute effects of low-to-moderate doses of psilocybin in healthy participants. This demonstrated that it was largely safe and feasible to engage in movement tasks during the acute drug effects up to a dose of 15mg psilocybin, informing the dosing and design for this follow-up study in FND participants.

This follow-up pilot study in refractory motor FND will explore the feasibility, safety, and possible efficacy of psilocybin-assisted physiotherapy in this cohort. Additional outcomes will assess expectancy, subjective drug intensity, mood, anxiety, somatic symptoms, life impact of the disease, motor function, movement quality, personality, force-matching physiology, and resting-state and task-based brain activity. The findings may also inform studies of psychedelic-assisted therapy in other FND sub-types, functional disorders, and neuropsychiatric disorders associated with motor dysfunction.

This is a highly collaborative and interdisciplinary initiative involving researchers with backgrounds in psychiatry, psychology, neurology, neuroimaging, physiotherapy, trial design and statistics, law, and consumer representation.

The findings from this pilot study will also inform the design of a larger, planned randomised controlled trial of psilocybin-assisted physiotherapy in refractory motor FND which has received funding from the Medical Research Future Fund.