Are there 'casual users' of cocaine?

Medical and public opinion about cocaine use have shifted dramatically over the past decade. New research methodologies and definitions to evaluate the impact of cocaine are needed. This paper presents a theoretical definition and empirical analysis of the 'casual user' of cocaine. Data have been drawn from a subsample of 58 cocaine users and their cocaine-using contacts in Rotterdam. The methodology of the study presents a novel approach to patterns of cocaine use involving the integration of social network variables with 'snowball' sampling data collection techniques. The theoretical definition is systematically related to two social context variables: (1) the scope of settings where contacts use cocaine; (2) the degree of involvement in social network relations of actual cocaine use. Scope of settings has been defined in terms of the number of cocaine-using social circuits contacts are drawn from: i.e. 'narrow' setting where all contacts originate from one circuit while a 'wide' setting indicates contacts come from two or more circuits. Involvement has been defined in terms of the percentage of contacts where the relation with study participants is characterized by cocaine use most or all of the time. Additional social network variables measuring the mean duration (in years) of contacts' cocaine use and the use of cocaine with contacts in the last six months are subsequently related to the scope and involvement variables. The implications of the analysis for a new cross-classification of cocaine use patterns are discussed with special reference to public health policy issues.