3. Psychedelics — The Community Origin of a Research Agenda

This is the best-documented case of community-led citizen science directly generating a formal academic research programme in headache medicine.

From bulletin board to Harvard: Sewell, Halpern & Pope (2006)

Building directly on the online reports described in Section 1, R. Andrew Sewell, John H. Halpern, and Harrison G. Pope Jr. of McLean Hospital/Harvard Medical School conducted a retrospective interview survey of 53 CH patients who had self-administered psilocybin or LSD outside clinical settings, verifying diagnoses against medical records peer-reviewed2627. Published in Neurology in 2006, the results were striking: 22 of 26 psilocybin users reported the drug aborted attacks; 25 of 48 psilocybin users and 7 of 8 LSD users reported cluster period termination; 18 of 19 psilocybin users and 4 of 5 LSD users reported remission period extension peer-reviewed266. Notably, this was the first paper to document that sub-hallucinogenic (“sub-perceptual”) doses could be effective, a detail directly derived from patient self-report protocols rather than any prior pharmacological theory peer-reviewed2829. Nature’s contemporaneous news coverage highlighted that 85% of psilocybin users reported aborted attacks, versus 52% for oxygen in the same surveyed population — though this cross-treatment comparison came from self-report, not a head-to-head trial peer-reviewed6.

The 2015 Clusterbusters Medication Use Survey (Schindler et al.)

A second, larger analysis — again built on the community-collected Clusterbusters Medication Use Survey (496 respondents) — found indoleamine hallucinogens (psilocybin, LSD, and lysergic acid amide/morning glory seeds) rated comparable to or more effective than most conventional medications, both for aborting attacks and inducing remission of chronic CH, and again found infrequent, non-hallucinogenic doses reported as efficacious peer-reviewed133028.

Yale/VA controlled trials (Schindler et al.)

Emmanuelle Schindler at Yale/VA Connecticut ran the first controlled investigations of psilocybin in CH:

• A 2022 randomised, double-blind, placebo-controlled pilot trial (14 patients, low-dose “pulse” regimen of ~10.6 mg psilocybin per session, 3–7 days apart) found a mean reduction of 3.2 attacks/week versus placebo’s 0.03 increase over three weeks — not statistically significant overall (moderate effect size d=0.69), but a large effect size (d=1.25) in the chronic CH subgroup versus a small effect (d=0.35) in episodic CH peer-reviewed3132. No serious adverse events occurred; symptom relief was not correlated with the intensity of the psychedelic experience itself peer-reviewed3132.
• A 2024 blinded extension of that trial (10 participants, second round of dosing ≥6 months later) found attack frequency dropped from a baseline of 18.4/week to 9.8/week (~50% reduction) in the three weeks following the first dose of the second round, regardless of whether the participant had responded during round one peer-reviewed333435.
• An open-label study, EPOCH (NCT04280055), in chronic CH was designed to test the same low-dose psilocybin pulse regimen for a 30% attack-frequency reduction (P=.008) peer-reviewed36. Correction (checked August 2026): the ClinicalTrials.gov record for NCT04280055 shows this study was actually TERMINATED, with the stated reason “Not possible to achieve the anticipated no. of patients due to Covid-19 pandemic”; actual enrolment reached only 10 participants against a larger target, with completion recorded in June 2022 preprint / trial36. A partial-data publication exists (PMID 38238974), but this should be understood as a curtailed, underpowered study rather than a completed trial that hit its pre-specified target — the earlier framing in this chapter overstated its completeness peer-reviewed36.

The consistent, cross-study finding that therapeutic benefit is dissociated from the intensity of the acute psychedelic experience is an important and somewhat unexpected result — it undercuts the intuitive assumption that a “full trip” is necessary, and directly validates what community members had reported for two decades about sub-hallucinogenic dosing peer-reviewed3229.

Update (checked August 2026): no new completed CH-specific trial results from the Schindler/Yale group were located beyond the above. The most chapter-relevant new item is a direct extension of the citizen-science pattern this chapter documents: Schindler, Lenaburg, and Clusterbusters founder Bob Wold co-authored a 2026 conference abstract, “DMT use in Cluster Headache: Interim Analysis of an International Survey,” presented at the American Academy of Neurology and indexed in Neurology citizen sciencepeer-reviewed81 — a formal academic researcher and the community’s own founding advocate co-running a new survey on a psychedelic (DMT) that has not yet appeared elsewhere in the formal literature on CH. This is presently only an interim conference abstract; full results are pending. Separately, a 2026 case series (Leighton et al.) and a registered Phase 2 LSD trial in chronic CH (NCT05477459) extend the pipeline but were not located in enough detail to summarise responsibly here peer-reviewed82.

BOL-148: turning a psychedelic into a non-hallucinogenic drug candidate

BOL-148 (2-bromo-LSD) is structurally related to LSD but lacks (or greatly attenuates) hallucinogenic activity at typical study doses, while retaining serotonin receptor activity relevant to CH peer-reviewed3738. A German-American collaboration (Matthias Karst and Torsten Passie at Hannover Medical School, with John Halpern at Harvard) ran an open, non-randomised case series of five chronic, treatment-refractory CH patients given three doses of BOL-148 five days apart; the cluster cycle was interrupted in all five, with remissions lasting from months to years, and side effects were minimal to none peer-reviewed3739. This is explicitly a Hannover (Germany)-originated, non-English-language-team result, though published in the English-language journal Cephalalgia peer-reviewed37. The authors themselves caution these results are preliminary — unblinded and uncontrolled peer-reviewed37.

As of August 2026, Ceruvia Lifesciences has raised US$8 million (announced 3 August 2026, founder-backed by CEO Carey Turnbull) to complete an integrated Phase 1/2 trial of BOL-148 (also referenced under code names TD-0148A/NYPRG-101): Part 1 is a single-ascending-dose study in healthy adults, Part 2 a randomised, placebo-controlled Phase 2 proof-of-concept in CH patients preprint / trial4041. A Clinical Trial Application is planned for submission in Germany in September 2026, with first patient enrolment expected Q4 2026 and Phase 1 top-line data anticipated Q2 2027 preprint / trial40. As of this update, no participant has yet been dosed under this new trial and no Phase 1 data exist — this remains squarely trial-pipeline territory, not yet an approved treatment, and given that BOL-148/Ceruvia’s timelines have slipped for well over a decade since the original 2010 Hannover case series, 2027 readouts should be treated as aspirational rather than assured preprint / trial40.

A related but distinct compound, BETR-001, developed by a different company (BetterLife Pharma) and described as a 6R:9R stereoisomer in the same chemical family, remains at an earlier, preclinical stage as of a July 2026 investor presentation: an IND filing is expected Q1 2027, with Phase 1A/1B to start around the same time and safety/proof-of-concept data 12–18 months after that preprint / trial83. This should not be confused with Ceruvia’s BOL-148 programme — the two are separate companies pursuing related but distinct molecules, and conflating them (as some secondary sources do) overstates how far either has actually progressed.

Legal status by jurisdiction, including Australia

Psilocybin and MDMA remain Schedule 9 (Prohibited) substances as raw materials in Australia, but from 1 July 2023 the Therapeutic Goods Administration rescheduled final preparations of psilocybin (Schedule 8) for use only in treatment-resistant depression, prescribable exclusively by TGA-Authorised Prescribers [PEER-REVIEWED/regulatory]4243. Cluster headache is not a TGA-approved indication for psilocybin prescribing in Australia; any CH-related use would need to occur within an approved clinical trial [regulatory fact]42. Notably, Australia is host to one of the world’s first funded clinical trials specifically targeting CH: the PEACE pilot trial (Psilocybin Efficacy and Acceptability on Cluster Headache Episodes), led by Dr Faraidoon Haghdoost at The George Institute for Global Health and UNSW Sydney, funded through the Medical Research Future Fund (reported at AUD $800,000) and testing 10 mg psilocybin weekly for four weeks against placebo in a planned 40-patient randomised controlled design with 6-hour post-dose monitoring — described as the first newly approved CH treatment trial in Australia in at least two decades [PEER-REVIEWED/institutional]4484.

Update (checked August 2026): the PEACE trial has not yet started recruiting. Dr Haghdoost’s own September 2025 announcement stated recruitment “has not started yet — we expect this to begin in the second half of next year” (i.e. H2 2026) preprint / trial85, and a March 2026 webinar advertised by his practice still described PEACE as an “upcoming” trial preprint / trial86. No ANZCTR or ClinicalTrials.gov registration number could be located for it in this research — a ClinicalTrials.gov search for cluster headache plus psilocybin plus Australia returned zero results, and ANZCTR’s own search tool blocks automated access, so a definitive registration check would need to be done manually at anzctr.org.au [unverified]85. No interim or final results exist yet; treat this trial as funded and designed, not yet running, with any results at best a 2027 prospect once recruitment (H2 2026 earliest) and the trial itself conclude.

A directly relevant and newly published piece of citizen-science-adjacent research has emerged from the same Australian team: Haghdoost et al., “Patient perspectives on research gaps in cluster headache,” Headache (2026), co-authored with Clusterbusters founder Bob Wold and recruited through patient advocacy channels citizen sciencepeer-reviewed87. Of 202 analysed respondents (mean age 46, 55% male, 72% with CH for more than 10 years), 35% rated their treatments as ineffective or only somewhat effective, and the most commonly cited challenges were treatment ineffectiveness (74%), side effects (54%), and cost (53%). 62% of respondents were interested in participating in future trials, and among those “very interested,” psilocybin ranked as the top treatment of interest at 66% (ahead of anti-CGRP therapies at 66% combined-interest and devices at 71% combined-interest, with combination therapies highest overall at 84%) citizen sciencepeer-reviewed87. This survey is itself a small piece of the same community-informs-formal-research pattern this chapter documents throughout, now happening on Australian soil ahead of the PEACE trial it will presumably help justify and recruit for.