A decade ago, behaviourists were operating almost entirely on three models, classical conditioning, operant conditioning, and social learning theory. Since then, there has been a quiet revolution and behaviour therapy has ‘gone cognitive’ with cognitive-behavioural (CB) models joining the previous trio. Acceptance of CB models into the theoretical base of behaviour therapy legitimizes a focus on individuals’ interpretation of events. No longer does the focus have to be entirely on discrete and visible behaviour, or on changes which are visible on some physiological measuring instrument. The cornerstone of CB models is the assumption that individuals’ interpretation of events can have an important influence on their emotional state and behaviour. Though there are divergences amongst CB models there is a consensus that thought processes, emotions, and behaviour are interdependent.