Clinical programs tend to fall into two categories: those that train practitioners and those that train researchers.

"The goal of our program is to provide people with excellent research training and high-quality clinical training, but the assumption is that the majority of our students will go into clinical research careers of one form or another" says Hooley. "This is not really a program that would be suitable for someone who wanted to go into private practice."

A therapist trained to bring purely clinical orientation to their work might find themselves swamped by the increasing technical nature of journals.

At Countway Medical Library, basement shelves are full of specialized journals covering the biological and social and psychological aspects of behavior.

And the field is changing rapidly.

Neurobiology is seen by many clinicians and researchers as the key to understanding mental illnesses, while others stress the interrelation between mind, brain and behavior.

The field has also prospered in the past decade because clinicians have emphasized their skills and training as scientists, using empirical methods to test theories of abnormal behavior and treatment.

"In order to be a good therapist, you have to think like a researcher...you have to develop hypotheses about what's going on, you have to test those hypotheses, you have to be able to document changes" says Hooley.