Comparison of the Chromosomal Patterns Obtained from Groups of Continued Users, Former Users, and Nonusers of LSD-25

Chromosome analyses in a single-blind study of heavy LSD users (current and former) and drug-free controls found no significant differences in chromosome breakage rates among the groups. Mean breakage rates were 1.8 percent or less for all three groups, failing to support earlier claims that LSD ingestion increases chromosome aberrations compared to a normal control population. The authors call for a more controlled longitudinal study.

Study at a glance

Abstract

In a single-blind study chromosome analyses were performed on three groups of subjects: 1) nine heavy users of LSD-25 who have continued to use the drug; 2) eight heavy users of LSD-25 who have ceased to use it; and 3) eight drug-free control subjects. The results revealed no significant differences in chromosome break-age rates between any of the three groups and therefore no temporal factor was elicited regarding chromosome damage and LSD ingestion. The mean breakage rates for all three groups were 1.8 percent or less and did not support earlier findings that LSD ingestion causes an increase in chromosome aberrations over those observed in a normal control population. The authors emphasize the need for a more controlled longitudinal study.