Therapeutic Advances in Psychopharmacology
January 1, 2020
Matthew Butler, Mathieu Seynaeve, Timothy R. Nicholson et al.
38 citations
Functional neurological disorder (FND), previously called conversion disorder, is common in neurology clinics and causes substantial disability, but treatment options are limited. Psychedelics like psilocybin and LSD may help by altering brain circuits involved in self-representation, which is thought to be disrupted in FND. A systematic review of nine studies from 1954 to 1967, involving 26 patients, found that most received psychotherapy with variable adjunctive psychedelic use (psycholytic therapy). Of those treated, 69% (18 patients) showed at least some recovery on subjective clinician-rated criteria. Adverse events were mostly mild, though one patient withdrew due to distressing effects. All studies were low quality, lacking controls and valid outcome measures, so no conclusions on efficacy can be drawn.
Journal of Neuropsychiatry
May 17, 2022
Matthew Butler, Mathieu Seynaeve, Abigail Bradley‐Westguard et al.
6 citations
Almost half of people with functional neurological disorder (FND) report having tried legal psychoactive substances—nicotine, alcohol, and cannabidiol—to manage their symptoms, finding them modestly effective. Fifteen percent have used illicit substances, mostly cannabis, reporting moderate effectiveness and minimal side effects. Many respondents (46%) would be willing to try medically supervised psychedelic therapy if proven safe and effective. The findings highlight that people with FND often seek alternative symptom management outside usual medical care and suggest that further research into novel treatments, including psychedelics, may be warranted.
Wellcome Open Research
April 22, 2025
Matthew Butler, Catherine Bird, Carolina Maggio et al.
3 citations
Functional neurological disorder (FND) is a common, debilitating condition linked to abnormal brain networks, dissociation, interoception, and motor agency. This open-label neuroimaging protocol will administer 25 mg of oral psilocybin with psychological support to 24 people with chronic FND. Resting-state and task-based functional MRI sequences will be compared before and after psilocybin. Additional measures include interoception, somatisation, illness perceptions, suggestibility, and dissociation. Participants will be followed for three months. The study aims to probe mechanisms underlying FND and assess the safety and feasibility of psychedelic administration with psychological support in this population.
Translational Psychiatry
April 24, 2026
Matt Butler, Ellen Moore, James Rucker et al.
1 citation
Hallucinogen persisting perception disorder (HPPD) involves episodes of altered perception after past psychoactive drug use, causing distress and impairment. In a large retrospective cohort study using electronic health records from 25,778 individuals diagnosed with HPPD, high rates of prior comorbidities were found, including depressive episodes (29.2%), anxiety disorders (26.2%), chronic pain (15.9%), headache syndromes (14.7%), post-viral fatigue (12.3%), ADHD (6.6%), and fibromyalgia (6.7%). Anxiety and functional somatic syndromes were more common in HPPD patients than in psychedelic-using controls. Anxiety (odds ratio 1.5) and post-viral fatigue (odds ratio 1.9) predicted HPPD development among psychedelic users. After diagnosis, HPPD was associated with increased risk of subsequent functional somatic syndromes (odds ratio 2.0) and psychiatric disorders (odds ratio 1.4) compared to psychedelic-using controls.
Journal of Neurology Neurosurgery & Psychiatry
July 20, 2020
Matthew Butler, Mathieu Seynaeve, Timothy R. Nicholson et al.
Functional neurological disorder (FND) causes significant disability, yet treatment options are limited. A systematic review of nine studies from 1954–1967 involving 26 patients found that psychedelics, primarily LSD (25–2,000 mcg) and psilocybin (3–15 mg), were used alongside psychotherapy. After treatment, 69% of patients showed at least some recovery, and 23% fully recovered. Adverse events were mild and transient. Although the studies were low quality and lacked control groups, the degree of improvement suggests psychedelics may be a promising treatment for FND, warranting modern research.