Does Psychotherapy Change the Brain?

Research in the area of neuroscience shows increasingly that the mind and body are intricately intertwined. Many brain imaging studies show that psychotherapy can actually lead to structural and functional changes in the brain. Beliefs that the brain stops growing are nowadays refuted and we know that there is actual growth of new cells well into the 60s and that experiences and the environment have an effect on the brain structure. Psychotherapy does actually alter the structure of the brain, just as exercises and other environmental factors have an influence on the brain. Helen Mayberg of Emory University, for example, has done studies comparing antidepressants with cognitive behavioral therapy (CBT) and found that CBT affects the frontal lobes–the “higher” part of the brain responsible for cognition–while fluoxetine (Prozac) goes to work on the amygdala–the “bottom,” emotional part of the brain.

It’s not just CBT that causes changes in the brain; studies by psychiatrist Hasse Karlsson have found that short-term psychodynamic therapy does the same in people with depression, as do studies by Schnell and Herpertz using dialectical behavioral therapy.

But critics of brain imaging studies note that the instruments have been too crude to really tell us much of anything. Brain imaging works primarily by measuring increases and decreases in blood flow to relatively large areas of the brain—a sign of neural activation or de-activation—and, critics say, drawing conclusions from this is roughly equivalent to studying the Earth’s geology by using photographs from the Hubble telescope.

But reviewing 20 years of studies of neuroimaging and psychotherapy in the August 11, 2011 Psychiatric Times, Karlsson points out that continuing refinements and new techniques of neuroimaging now enable us to study the brain at a much more precise level—down to a molecular level. We can now look at the synapses that control the flow of neurotransmitters like serotonin and dopamine. Karlsson cites a study by Lehto that finds that after a year of psychodynamic therapy, the brains of patients with atypical depression had developed denser connections in the synapses controlling serotonin; this is roughly equivalent to taking an SSRI antidepressant such as fluoxetine.

In one of his own studies, Karlsson administered fluoxetine to one group of depressed patients and short-term psychodynamic therapy to the other. Both groups showed clinically significant reductions in depression symptoms, but only the group receiving the psychotherapy showed greater density in the synapses. Karlsson speculates that the change in neural structure found in this study may account for the well-known fact that depressed people treated with psychotherapy are less likely to suffer recurrence than are people treated with only antidepressants.

Of course, these recent studies are still preliminary. The Lehto study had a small number of participants, lacked a control group, and found synaptic changes only in patients with atypical depression, a puzzling finding with no clear explanation as yet. Both Lehto’s and Karlsson’s studies need replication before the findings can be considered more important. But taken with two decades of other brain scans, the evidence is growing that psychotherapy can induce restructuring of the brain.

Karlsson’s article, “How Psychotherapy Changes the Brain,” may be found in the August 11, 2011 Psychiatric Times, 28(8).