Psychotherapy induces measurable changes in brain structure. A new study published in Translational Psychiatry by researchers from Martin Luther University Halle-Wittenberg (MLU) and the University of Münster has demonstrated this using cognitive behavioral therapy (CBT).
Translational PsychiatryThe researchers analyzed the brains of 30 patients with severe depression. After undergoing CBT, most participants exhibited changes in areas responsible for emotion processing. These effects are comparable to those observed in medication-based studies.
Approximately 280 million individuals worldwide suffer from severe depression, which impacts brain mass in the anterior hippocampus and amygdala—key parts of the limbic system that process emotions. CBT is a widely used method for treating depression.
"CBT leads to positive changes in thoughts, emotions, and behavior," says Professor Ronny Redlich, head of the Department of Biological and Clinical Psychology at MLU. "We hypothesized these changes are linked to functional and structural brain alterations." While previously demonstrated with medication or electrostimulation, this effect had not been proven for general psychotherapy.
The study employed structural magnetic resonance imaging (MRI) to examine participants' brains before and after 20 therapy sessions.
Psychologist Esther Zwiky of MLU explains: "MRI scans provide details about tissue size, shape, and location." The study also included clinical interviews assessing symptoms like difficulty identifying emotions. Additionally, 30 healthy control subjects (not undergoing therapy) participated for comparison.
The findings were clear: 19 out of the 30 patients showed minimal depressive symptoms after therapy. For the first time, specific anatomical changes were documented.
"We observed a significant increase in gray matter volume in the left amygdala and right anterior hippocampus," says Zwiky. These increases were linked to improved emotion regulation—patients with higher gray matter increases also demonstrated stronger reductions in emotional dysregulation.
While CBT's effectiveness was already known, Redlich notes: "For the first time, we have a reliable biomarker for psychotherapy's effect on brain structure." However, he emphasizes that not all treatments are universally effective—some people respond better to medication or electrostimulation, while others benefit most from CBT.
"Our study confirms that psychotherapy is an equally valuable treatment option," says Redlich.