THE INCREASED abuse of lysergic acid diethylamide (LSD) has aroused popular concern for its complications and has led the leading pharmaceutical manufacturer to withdraw its supplies from investigational use. Recent reports, especially those in the lay press, give the impression of an increasing incidence of persistent psychoses, associating the observations with the illicit use of LSD.1,2
The experimental LSD experience in medical settings is usually described as transient, limited to a few hours or at most a day. The persistence of ideational or emotional changes beyond 24 hours may be defined as "prolonged effects" and these have been reported in surprisingly few subjects.3,4 The descriptions of these prolonged adverse effects generally include spontaneous recurrences of the acute LSD experience, persistent psychotic decompensations, induced depression with attempted and completed suicides, and multihabituation. The durations of these states range between one week and two years, with about 40% of the