[The substance experience, a history of LSD].

This article reviews the recent knowledge on LSD stemming from various disciplines among which pharmacology, sociology and epidemiology. The d-lysergic acid diethylamide (LSD) is a particularly powerful hallucinogenic substance. It produces distortions and hearing, visual and tactile hallucinations. Rarely used (only 1.7% of people aged 15-64 years old have tried it in their lifetime), this very powerful drug generates a strong apprehension within the general population, but the ethnographical studies show that its image seems rather good among illicit drug users. This representation relies both on the proper effects of this substance and also on the history of LSD very closely linked to the counterculture characteristic of the years 1960-1970.