Functional neurological disorder (FND) causes seizures and movement disorders, is debilitating, and often has a poor prognosis. Brain imaging suggests FND involves multiple networks, and mechanisms like dissociation and abnormal motor agency may play a role. Psychedelics disrupt brain networks and are being tested for neuropsychiatric disorders. This open-label neuroimaging study will give 25 mg oral psilocybin with psychological support to 24 people with chronic FND. Resting-state and task-based fMRI, plus measures of interoception, somatisation, and dissociation, will be collected before and after psilocybin, with three-month follow-up. The study aims to probe FND mechanisms and assess safety and feasibility of psychedelic administration in this population.
Placebo effects remain a major paradox in medical research, with more data available from placebo-controlled trials than on any treatment, yet little deep analysis of how they are measured, appraised, and interpreted. This review shifts focus from clinical practice to clinical trials, examining established and emerging approaches for managing placebo effects in randomized controlled trials. It highlights three key challenges in contemporary psychiatric research: blinding and expectancy in psychedelic trials, large placebo responses in interventional psychiatry trials (device or procedure-based treatments), and the implications of overlapping neurobiological mechanisms between placebo effects and psychiatric treatments.