This was the last report in a series of three based on a study of 100 Irish drug abusers. All three papers reported on a research project organised by the Economic and Social Research Institute in conjunction with the Jervis Street Drug Advisory and Treatment Centre. All subjects included in the investigation had attended a drug advisory and treatment centre in Dublin for the first time between November 1977 and February 1979. Drug abusers were defined as individuals who, as a result of taking psychoactive drugs, had suffered medical, psychological or social complications. This article presented a psycho-social typology of drug abusers, which was established on the basis of extensive interviews and psychological test data.

Three psycho-social scales were administered to each subject: Davisí (1976) Anomie Scale; Hartís (1977) Modified Locus of Control Scale; and a short form of Crumbaughís (1968) Purpose in Life Scale. The typology established consisted of four major groups, which accounted for 94% of the cohort, and three dyads. The largest group, containing 36 of the subjects, was labelled the Extragressors; it was made up of young, aggressive, criminal, subcultural, poly abusers, who came from highly inadequate working-class families. The second largest group, accounting for 26 subjects, was called the Self-Medicators; these were older, passive, anxious barbiturate or minor tranquilliser misusers, who had been introduced to drugs through medical or psychiatric treatment. The other groups fell somewhere on the continuum from subcultural deviance to personal inadequacy