A follow-up survey of 247 persons who received d-lysergic acid diethylamide (LSD) in either an experimental (nonmedical) or Psychotherapeutic setting was made to determine the lasting effects, if any, related to use of the drug. Information was collected from each by a structured interview and self-administered questionnaire. Some subsequent nonmedical use of LSD was reported by 23%, who attributed more personality changes to the drug's use. There is, however, little evidence that measurable, lasting personality, belief, value, attitude, or behavior changes were produced in the sample as a whole. Compulsive patterns of LSD use rarely developed; the nature of the drug effect apparently is such that it becomes less attractive with continued use and, in the long-term, is almost always self-limiting.
McGlothlin WH, Arnold DO. LSD RevisitedA Ten-Year Follow-up of Medical LSD Use. Arch Gen Psychiatry. 1971;24(1):35-49. doi:10.1001/archpsyc.1971.01750070037005