Classical conditioning is the basis of the behaviorist approach to therapy in the United States, and can be used quite successfully by the clinical psychologist to help a client overcome maladaptive behaviors, attitudes, or habits. These problems range from negative attitudes and thought processes to quitting smoking or over coming a neurosis or fear of something. This works because in many cases the problem habits or behaviors are learned and simply need to be unlearned, or replaced by another learned experience.
In experiments, this means dogs learning to salivate at the ring of a bell, while cats learn to avoid a room that has given them electrical shocks (or unlearning that behavior). In practice, however, this translates to something as simple as retraining a depressed patient to think different automatic thoughts. Other forms of classical conditioning can be rewarding a neurotic patient for positive behaviors, counterconditioning by replacing an anxiety response with an anger response, or using systematic desensitization to overcome fear of a particular object, such as the fear of bugs. Even providing a model that the client can identify with may both ease the stress of learning a new behavior, while also providing a positive response for learning a new behavior.
Halgin, R. P. & Whitbourne, S. K. (2003). Abnormal Psychology: Clinical Perspectives on Psychological Disorders. New York, NY: McGraw-Hill Companies, Inc.
...