I found this bit on the second page fascinating:

One of the major insights in the modern biology of learning and memory is that education, experience, and social interactions affect the brain. When you learn something and then remember it for a long time, it’s because genes are being turned on and off in certain brain cells, leading to the growth of new synaptic contacts between the nerve cells of the brain. Insofar as psychotherapy works and produces stable, learned changes in behavior, it can cause stable anatomical changes in the brain. We are now beginning to measure such changes with brain imaging. If a person with obsessive-compulsive neurosis or depression undergoes psychotherapy—and if the treatment is successful in changing behavior—the treatment will cause a reversal in the biological markers of these disorders.