Published: 25-05-2012 00:00 | Updated: 02-10-2018 14:36

Effects of CBT on brain biochemistry

Using Positron Emission Tomography (PET), researchers at Karolinska Institutet have shown an association between symptom reduction after psychotherapy and change in dopamine receptor levels, in patients with social anxiety disorder. The study provides new evidence on the interplay between psychological and biological factors in psychiatric disease.

Social anxiety disorder is a common psychiatric disorder, causing distress and impairments in functioning. Although effective treatment is available, not all patients attain symptom remission, and there is a lack of knowledge regarding the biological underpinnings of the disorder.

Molecular imaging techniques such as Positron Emission Tomography (PET) allow for in vivo investigation of brain neurotransmission. The neurotransmittor dopamine has previously been suggested to have a role in social anxiety disorder. In the present study, published in the scientific journal Translational Psychiatry, a group of patients with social anxiety disorder were examined using PET before and after treatment with cognitive behavioural therapy (CBT), which is considered to be the most effective form of psychotherapy for the disorder.

Involved in learning and social evaluation

A radioligand with high affinity for the dopamine D2 receptor was used, enabling measurements in brain regions of particular interest for social anxiety disorder. Despite a limited sample size, the study showed a statistically significant association between change in dopamine receptor levels and symptom reduction after psychotherapy, in brain regions previously shown to be involved in learning and social evaluation.

This is the first study to report a direct relationship between symptom change after psychological treatment and a marker of brain neurotransmission. The study supports a role for the dopamine system in the pathophysiology of social anxiety disorder.

– Due to the relatively small sample size more research is needed, however on a more general level the results illustrate how psychological and biological factors can interact in the treatment of psychiatric disorders, which can aid the development of new diagnostic tools and treatment strategies, says Dr Simon Cervenka, who was responsible for the study.


Changes in dopamine D2-receptor binding are associated to symptom reduction after psychotherapy in social anxiety disorder.
Cervenka S, Hedman E, Ikoma Y, Djurfeldt D, Rück C, Halldin C, et al
Transl Psychiatry 2012 May;2():e120