Demographic characteristics of groups classified by patterns of multiple drug abuse: a 1969-1971 sample.

Patient characteristics are described in relation to pretreatment usage combinations of eight classes of illicit drugs for 11,380 drug abusers admitted between 1969 and 1971 to drug treatment centers participating in the NIDA-TCU Drug Abuse Reporting Program. From these data, nine basic patterns of drug use were defined. The most frequent, involving the daily use of heroin or other opioids only, characterized 27% of the patients. Four patterns involving heroin (at least weekly) with various combinations of cocaine, barbiturates, and marijuana accounted for another 29%, two patterns of polydrug use (three or more nonopioid drugs, with and without opioids daily) included 16%, and the remaining 28% of the patients were represented by patterns of a less specific nature. The distribution of patients across drug-use patterns was unrelated to sex, but was associated with race-ethnic background and age.