Biology in the Service of Psychotherapy

Neuroscience has developed a number of useful methods for analyzing cognitive function. As a result, our understanding of normal and abnormal mental function has grown substantially. These insights have improved the ability to intervene pharmacotherapeuti-cally in the treatment of patients with mental illness. Can this new understanding also inform and improve psychotherapeutic interventions? Psychotherapy remains one of the cornerstones of treatment for many psychopathologies, including various personality disorders. There also is evidence that the combined use of psychotherapy and medications can lead to better treatment outcome (Newton-Howes and Tyrer 2003; Zanarini and Frankenburg 2001). Despite the extensive use of psychotherapy for a number of mental disorders, we lack a biological perspective on how psychotherapy works. Investigation of the biological underpinnings of psychotherapy is important for two reasons. First, an understanding of psychotherapy is important in psychiatry's attempt to link specific mental functions with specific brain mechanisms and may aid in the analysis of how the environment affects the brain. Psychotherapy is a controlled form of learning that occurs in the context of a therapeutic relationship—and from this perspective, the biology of psychotherapy can be understood as a special case in the biology of learning (Kandel 1979). Second, insight into the biological mechanisms of psychother-apeutic action would revolutionize psychiatry by enhancing our understanding of premorbid vulnerabili-ties, selection of the optimal course of therapy, and evaluation of treatment outcome. Because the neurobiological study of psychotherapy is in its infancy, any attempt to address the biology of psychotherapy at this early point will be incomplete. Nonetheless, the initial research into the biological underpinnings of psychotherapy has already provided several new insights. In this chapter, we outline where we are and how future refinements might advance the field further. Our discussion centers primarily on depression, obsessive-compulsive disorder (OCD), and anxiety, where neuroimaging work is most advanced. By con