Drug flashbacks. II. Some additional findings.

A subsample was drawn from an earlier collection of data in order to answer a number of questions related to "acid" (LSD, STP) flashbacks. Acid users who reported flashbacks also reported significantly more marijuana use than those who did not; the two groups did not differ on use of other drugs, including acid. Simple correlations and multiple regression analyses both showed extent of marijuana use to be the only drug variable significantly related to acid flashbacks. No optimal combination of marijuana and acid improved flashback prediction. Among acid users, correlations between amounts of use for various drugs were high and significant, excepting only the marijuana-acid correlation.