Cluster headaches occur several times a day. They start suddenly, last for a limited time, and can be very painful.

Attacks occur cyclically. A bout of regular attacks, known as a cluster period, can last a few days, weeks, or months. This is followed by remission periods, during which there are no headaches.

Cluster headaches are not common. They are thought to affect about 1 in every 1,000 people. Six out of 10 cases involve men, and most of these are smokers. It usually starts after the age of 20 years.

Psilocybin has VERY positive effects when treating cluster headaches.