Efficacy and Safety of Minidosing Lysergic Acid Diethylamide (LSD) for Chronic Cluster Headache: a Randomized Placebo-controlled Study
This study aims to investigate the efficacy and safety of LSD 25μg every 3 days for 3 weeks versus placebo in the treatment of chronic cluster headache (cCH). It is a 3-week double-blind placebo-controlled intervention study, preceded by a 4-week baseline observation period and followed by a 5-week post-treatment observation period. Primary objective: to evaluate the efficacy of LSD 25μg every 3 days for 3 weeks in cCH. Additional objectives: * To evaluate the safety of LSD 25μg every 3 days for 3 weeks in cCH. * To explore the exposure-response relationship of 25μg LSD in cCH. * To explore cost-effectiveness of treatment with LSD in cCH. * To evaluate the efficacy of LSD on health-related quality of life.
• CCH according to the International Classification of Headache Disorders version 3 (ICHD-3)
• At screening: stable weekly attack frequency in the 4 weeks prior to screening (assessed retrospectively), averaging at least 8 per week and each week within a 40% window around the average
• At randomization: average of at least 8 attacks per week and no absence of attacks on more than two consecutive days during baseline