On Friday, April 16, 1943, Swiss chemist Albert Hofmann felt ill and left his Sandoz laboratory mid-afternoon. Lying down at home, he reported that “there surged in upon me an uninterrupted stream of fantastic images of extraordinary vividness and accompanied by intense, kaleidoscope-like play of colors.” Suspecting a link between these effects and a chemical on which he had been working—initially synthesized in 1938 and then put aside—the following Monday he ingested an extremely small amount of the chemical: 250 micrograms (0.25 mg). Forty minutes later, during his “bicycle day” ride home and for the next six hours, disordered and multicolored images ran through his head.

Hofmann’s seemingly minute dose of lysergic acid diethylamine (LSD-25, lysergide) was actually five to ten times higher than a normal dose. (LSD is the most potent hallucinogenic substance known, acting in the brain at seemingly infinitesimal doses). His 1947 scientific report captured the attention of a widely diverse range of readers, including scientists, psychiatrists, the CIA, the army, and recreational users.

In the 1950s, when the biomedical community was focused on the brain and mental disorders, LSD was utilized to better understand the brain and to study the cause and treatment of schizophrenia. It was given to enhance psychotherapy sessions and to combat alcoholism.

The CIA and army conducted experiments with more than 1,000 soldiers and civilians, testing LSD’s potential to behaviorally disrupt the enemy and to elicit obedience in prisoners and spies. In the mid-1970s, when these army-sponsored 1950s-era studies were disclosed, it was obvious that ethical codes of human experimentation had been violated. Many of the subjects were not willing volunteers, neither were they informed about the nature and risks of the studies.

SEEING SOUNDS IN LIVING COLOR. Inspiring the emergence of psychedelic rock in the 1960s and 1970s, LSD has long attracted the interest of artists, writers, and musicians, who used LSD to expand their consciousness, creativity, and insights. Although experts have not found concrete evidence for such mind-altering effects, LSD can cause synesthesia (a mixing of the senses) in which sounds are seen. Research continues into possible beneficial effects of LSD for alcoholics, terminally ill patients, and others.