Lysergic Acid Diethylamide (LSD) as Treatment for Cluster Headache

Background: After no official research in humans in the last 40 years, research and therapeutic uses of the serotonergic psychedelic lysergic acid diethylamide (LSD) are now re-recognized and include its use in brain research, alcoholism, anxiety associated with terminal illness, and treatment of headache disorders. Specifically, LSD has been reported to abort attacks, to decrease frequency and intensity of attacks, and to induce remission in patients suffering from cluster headache (CH). Objective: To investigate the effects of an oral LSD pulse regimen (3 x 100 µg LSD in three weeks) in patients suffering from CH compared with placebo. Design: Double-blind, randomized, placebo-controlled two-phase cross-over study design. Participants: 30 patients aged ≥ 25 and ≤ 75 years with chronic or episodic CH with predictable periods lasting approximately 2 months and attacks responding to oxygen. Main outcome measures: Changes in frequency and intensity of CH attacks assessed with a standardized headache diary Significance: CH is often rated as the most painful of all primary headaches, which not only causes significant disability, but is also associated with enormous personal, economic, and psychiatric burden. At the moment, there is no specific treatment available for CH, but serotonergic compounds represent an important drug class, especially in the abortive management of cluster attacks. However, there is a need for new treatment approaches, as CH is also often insufficiently managed with available medication. This study will evaluate the potential benefit and safety of a treatment with LSD for patients with CH.