Explanation:

Dependence is easier to recognise than it is to define. Images of young men in squats injecting heroin, of the well-heeled snorting cocaine or of the inebriate under the railway arches may be reinforced by television, by press reports or by walking down the streets of any large town or city. Similarly, patients with drug- and alcohol-related problems form much of the day-to-day workload in casualties, general practice surgeries and hospitals.

Despite the enormous diversity of these patients and their problems, they have one thing in common. The solvent inhaler, the heroin user and the heavy drinker all misuse various substances and show signs of dependence upon them. This chapter is concerned with current views of the nature of that dependence, how it arises and its significance for the individual and for society.