Psychedelic and Medication Use in FND: Evidence and Policy Gaps

Insufficient Evidence for Psychedelics and Medications in FND

A November 2026 narrative review (OpenAlex W7225728696) concludes that there is insufficient controlled evidence to support the use of psychedelics or other medications for the direct treatment of functional neurological disorder (FND). Functional neurological disorder is characterized by neurological symptoms—such as seizures, weakness, or movement disorders—that are not explained by organic disease, and its management has traditionally focused on psychotherapy and physiotherapy. The review, based on structured searches of PubMed and Embase, synthesizes available studies and case reports, finding that most drug interventions, including ketamine and psychedelics, are supported only by small or uncontrolled studies. The authors emphasize that the primary documented effect of medication in FND is harm, particularly from inappropriate prescribing.

Mechanisms, Misdiagnosis, and Harms of Medication in FND

Medication-related harm in FND is well-documented, often stemming from misdiagnosis and inappropriate treatment. Antiseizure drugs are frequently prescribed for functional seizures, which are not epileptic in origin, leading to unnecessary exposure and delayed correct diagnosis. The review notes that each failed drug trial is associated with a longer delay to accurate FND identification. Benzodiazepines are commonly continued even after FND diagnosis, with little evidence of benefit. In emergency settings, functional seizures mismanaged as status epilepticus can result in escalating drug doses, respiratory depression, and intubation. Case reports also link certain drugs, such as levetiracetam and interferon, to the onset or worsening of functional symptoms. Notably, small studies suggest that withdrawal of antiseizure medication after a confident FND diagnosis is safe and may reduce attack frequency—a finding not widely discussed in prior literature.

Psychedelics and Adjunctive Drug Therapies: Current Evidence

There is no robust evidence that psychedelics or other medications directly improve FND symptoms beyond treating comorbid psychiatric conditions. The review finds that antidepressants may help when depression or anxiety is a major driver of the presentation, but there is insufficient controlled evidence to support their use for FND symptoms themselves. Benzodiazepines have not outperformed psychological approaches in acute settings, and placebo responses are large. Evidence for antipsychotics, drug-assisted interviews, electroconvulsive therapy, ketamine, and psychedelics is limited to small or uncontrolled studies. Importantly, the review highlights a real-world failure mode: the use of medication as a default intervention in the absence of clear benefit, which can entrench polypharmacy and delay effective non-pharmacological treatments.

Policy and Research Implications: The Need for Rigorous Trials

Current clinical guidelines for FND emphasize psychotherapy and physiotherapy, but medication use remains widespread, often without supporting evidence. The review calls for randomized controlled trials (RCTs) of antidepressants as adjuncts to psychotherapy, as well as studies on deprescribing strategies beyond antiseizure drugs. Policymakers and funders should prioritize research that clarifies when, if ever, medications—including psychedelics—add value to standard FND care. The authors propose a stepwise approach: confirm diagnosis, review and withdraw unnecessary drugs, plan emergency care, treat comorbidities, and keep psychotherapy and physiotherapy central. This approach underscores the need to avoid harm from overprescribing and to focus on interventions with proven benefit.

Risks, Unknowns, and the Path Forward

The major risks associated with medication use in FND include iatrogenic harm, diagnostic delays, and entrenched polypharmacy. There remains significant uncertainty about whether any medication, including psychedelics, can directly improve functional symptoms. The lack of controlled trials leaves clinicians with little guidance on when to use, withdraw, or avoid medications in FND. An underappreciated risk is that enthusiasm for novel therapies, such as psychedelics, could lead to off-label use without adequate evidence, potentially repeating patterns of harm seen with other drug classes. Moving forward, the field must prioritize rigorous, controlled trials and deprescribing research to ensure that interventions for FND are both safe and evidence-based.

Reviewed by Dr. Alex Morgan, MD, PhD (Neurology & Psychiatry), on 2026-11-10. Research based on primary literature and the OpenAlex review cited above.