Diagnosis of personality disorder: a radical behavioral alternative

From a radical behavioral perspective, a single, diagnostic system is unlikely to serve diverse purposes. Instead, ideal diagnostic systems should be developed to serve specific purposes. For example, the crucial proof required of a classification system designed to improve the outcome of psychosocial intervention would be that it enhance the clinician's influence on processes associated with client change. This means, in turn, that the change processes must be known or theoretically specified. As an illustration of this general approach to diagnostic classification, a specific behavioral theory is used to articulate processes of change in psychotherapy. The Axis II of the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) is then evaluated with respect to its ability to enhance clinicians' influence of these processes, found problematic, and an alternative classification criterion is proposed.