The British Journal of Psychiatry
Acute Adverse Reactions to LSD in Clinical and Experimental Use in the United Kingdom
NICOLAS MALLESON

Abstract

This survey of United Kingdom experience with LSD in clinical work covers some 4,300 subjects with a total of some 49,500 LSD sessions. There was an attendant suicide rate of 0.7 per 1,000 patients, a rate of 9 per 1,000 patients for psychosis lasting for more than 48 hours (from which some two-thirds recovered fully), and an accident rate of 2.3 per 1,000 patients. The survey is not one that permits clear comparison with other forms of psychiatric treatment, but the following conclusion is probably justified: treatment with LSD does give rise to acute adverse reactions, but if there is adequate psychiatric supervision and proper conditions for its administration the incidence of such reactions is not great.