Significant differences were found between opioid takers and non-takers among referrals to Jervis Street Drug Advisory and Treatment Centre, Dublin, for the following variables: Sex, Age, Employment Status, Prior Court Appearance, Solitary drug taking. First drug taken abroad. Injection history. Physical complications associated with drug taking, and Maternal psychiatric status (for referrals aged under 21). Further analysis indicated 6 types of abuse associated with particular personal and social circumstances: (1) Minor tranquillisers, (2) Barbiturates only or with minor tranquillisers, (3) Opioids only or mainly, (4) Cannabis and/or L.S.D. only, (5) Poly-abuse excluding opioids, and (6) Poly-abuse including opioids.In broad social terms, these 6 groups may be seen as representing psychiatric or personal inadequacy-groups (1), (2) and (3), subcultural deviance-(5) and (6), and subcultural hedonism in the context of poor family relationships-(4). Groups most at risk were considered to be in the following order-(2), (3), (6),(1). Finally, cluster analyses, using unweighted and weighted variables, were employed to test the significance of distinctions based on types (3), (4), (5) and (6). In general, similar groups were obtained.