An interactive theory of drug use is outlined which provides the framework for integrating current knowledge and initiating new research. The theory has as its major characteristics: 1) attempted comprehensiveness; 2) explicit design for empirical test using causal models; 3) differentiation of direct and indirect causes of drug use and the consequences of drug-taking; 4) the delineation of mechanisms associated with different stages of drug use. The theory is applied to major issues implicit in the design and implementation of primary and secondary prevention programs, as well as to issues in professional training and the evaluation of programs. The model is presented as an evolutionary one which will grow as new data and clinical experiences are collected.
