Privately printed pamphlet extolling the benefits of trepanation, by the Dutch medical student and LSD advocate who revived popular interest in the practice. Trepanation is the process of creating a hole in the skull. It is one of the oldest known surgical procedures, used for medical, ritual, and spiritual reasons. In modern medicine, refined forms of trepanation are used for exploratory diagnosis and relieving intracranial pressure. Throughout the 1960s, Huges argued that the natural ossification of the skull was an impediment to the flow of blood through the brain, and that trepanation would solve a myriad of mental issues. He attended medical school, but was refused his degree because of his psychedelic drug advocacy, and likely for naming his daughter Maria Juana. His experiments with LSD, marijuana, and standing on his head for long periods of time, convinced him that the only permanent way of expanding his consciousness was drilling a hole in his skull. In January 1965, to verify his claims, Huges trepanned himself at home with a dental drill. The experience convinced him and many of his friends (including writer Joey Mellen and Countess Amanda Feilding) that trepanation had untapped therapeutic potential. The subsequent wave of curiosity saw John Lennon trying to convince Paul McCartney to try it: "I said 'Look, you go and have it done, and if it works, great. Tell us all about it and we'll all have it" (cited in André). Trepanation, The Cure for Psychosis expands on Huges theory, initially set out in his 1964 illustrated scroll, The Mechanism of Brainbloodvolume (BVV). He continued to advocate for its adoption by the medical profession until his death in 2004. Charles André, "Evolving story: trepanation and self-trepanation to enhance brain function"