Cognitive behavioral therapy can alter brain structure and boost gray matter volume, study shows

Psychotherapy leads to measurable changes in brain structure. Researchers at Martin Luther University Halle-Wittenberg (MLU) and the University of Münster have demonstrated this for the first time in a study in Translational Psychiatry by using cognitive behavioral therapy.

The team analyzed the brains of 30 patients suffering from acute depression. After therapy, most of them showed changes in areas responsible for processing emotions. The observed effects are similar to those already known from studies on medication.

Around 280 million people suffer from severe depression worldwide. This depression leads to changes in the brain mass of the anterior hippocampus and amygdala. Both areas are part of the limbic system and are primarily responsible for processing and controlling emotions. In psychotherapy, cognitive behavioral therapy (CBT) is an established method for treating depression.

“CBT leads to positive changes in thought patterns, emotions and behavior. We assume that this process is also linked to functional and structural changes in the brain. The effect has already been demonstrated with therapy involving medication or electrostimulation, but has not yet been proven for psychotherapy in general,” says Professor Ronny Redlich, who heads the Department of Biological and Clinical Psychology at MLU.

Now the researchers have succeeded in demonstrating this in their study. Structural magnetic resonance imaging (MRI) was used to examine the participants’ brains before and after 20 sessions of therapy.

“MRI scans provide information about the size, shape and location of tissue,” explains psychologist Esther Zwiky from MLU. In addition to the MRI scans, clinical interviews were conducted to analyze the symptoms of the disease, such as difficulty in identifying and describing feelings. In addition, 30 healthy control subjects, who did not undergo therapy, participated in the study for comparison purposes.

The study provided clear results: 19 of the 30 patients were found to have hardly any acute depressive symptoms after therapy. The researchers were also able, for the first time, to document specific anatomical changes.

“We observed a significant increase in the volume of gray matter in the left amygdala and the right anterior hippocampus,” says Zwiky. The researchers found a clear connection to the symptoms: Individuals with a greater increase in gray matter in the amygdala also showed a stronger reduction in their emotional dysregulation.

“Cognitive behavioral therapy was already known to work. Now, for the first time, we have a reliable biomarker for the effect of psychotherapy on brain structure. Put simply, psychotherapy changes the brain,” explains Redlich. However, Redlich stresses that there is no fundamentally better or worse treatment—medication works better for some people, while electrostimulation works very well for others; for others, CBT can be most helpful.

“It is therefore all the more encouraging that we were able to show in our study that psychotherapy is an equally effective alternative from a medical and scientific standpoint,” says Redlich.