Abstract
Risk is usually defined in terms of the probability and magnitude of loss (Yates and Stone, 1992). So when individuals engage in activities which are seen as detrimental to their health, medical science has sought to explain such decisions in terms of loss mediation (Janz and Becker, 1984; Ajzen, 1991). Common to these models is the belief that the individuals perception of the external, objectively defined health threat has the primary impact on their subsequent behaviour. When individuals fail to curtail risky activities, one explanation may be that they have an incomplete understanding of the health threat or, in the case of habitual drug use, because addicts have also relinquished their free-will and are no longer able too operate within the bounds of rational behaviour.