Then (1979), LSD: My Problem Child
Cluster Headaches and LSD: The Orphan Indication Hofmann Didn't Know About
Hofmann documented LSD's effects across psychiatric conditions but was not aware of its effects on cluster headaches, perhaps the most painful condition a human being can experience, often called 'suicide headaches' due to their intensity. No clinical trials for cluster headaches were conducted before the 1968 scheduling.
partially-confirmed
Patient-led research (Clusterbusters organization, founded 2002 by Bob Wold after his own experience) documented that sub-psychedelic doses of psilocybin and LSD, doses that do not produce hallucination, reliably abort cluster headache cycles and prevent recurrence. Sewell, Halpern, and Pope (Neurology, 2006) published the first retrospective study confirming the effect in 53 patients. The mechanism is unknown, cluster headaches involve the trigeminal nerve, not the serotonin system. Phase 2 trials are underway (Yale, Imperial College). The effect size is remarkable: patients who have tried every available treatment including surgery report 80-90% remission. This is a major therapeutic application of a Hofmann compound that was not discovered until patients discovered it for themselves, after fifty years of prohibition prevented formal research.
Sources
- Sewell, Halpern & Pope, Neurology (2006)
- Clusterbusters Patient Registry
- Imperial College London cluster headache trial (ongoing 2026)