News | May 07, 2008

SPECT Reveals Dopamine, Social Anxiety Link

May 7, 2008 - Using single-photon emission computed tomography (SPECT), researchers in The Netherlands were able to detect biochemical differences in the brains of individuals with generalized social anxiety disorder (also known as social phobia), providing evidence of a long-suspected biological cause for the dysfunction.

The study, which was reported in the May issue of the Journal of Nuclear Medicine, compared densities of elements of the serotonin and dopamine neurotransmitter systems in the brains of 12 people diagnosed with social anxiety disorder, but who had not taken medication to treat it, and a control group of 12 healthy people who were matched by sex and age.

Both groups were injected with a radioactive compound that binds with elements of the brain’s serotonin and dopamine systems. Once administered, the radiotracer revealed functional alterations in these systems by measuring the radioactive binding in the thalamus, midbrain and pons (known to be acted upon by serotonin) and in the striatum (known to be acted upon by dopamine). The altered uptake activity in these regions indicated a greater level of disordered function.

“Our study provides direct evidence for the involvement of the brain’s dopaminergic system in social anxiety disorder in patients who had no prior exposure to medication,” said Dr. van der Wee, M.D., Ph.D., at the department of psychiatry and the Leiden Institute for Brain and Cognition at the Leiden University Medical Center, Leiden (and previously at the Rudolf Magnus Institute of Neuroscience, University Medical Center in Utrecht, The Netherlands). “It demonstrates that social anxiety has a physical, brain dependent component.”
Serotonin and dopamine (neurotransmitters, or substances responsible for transferring signals from one neuron to another) act upon receptors in the brain. If the neurotransmitters are out of balance, messages cannot get through the brain properly. This can alter the way the brain reacts to normal social situations, leading to anxiety.

Other neuroimaging studies have shown abnormalities in glucose and oxygen consumption in the brain, according to van der Wee, who also points to causality as an additional issue. “Most of the people involved in these earlier studies were known to be already suffering from the disorder, so we do not know if the abnormalities were present before the onset of the disorder,” he said.

Based on earlier studies, some researchers have suggested that social anxiety disorder is a result of the interplay between a genetic or acquired biological vulnerability and environment. More recent research has indicated that social anxiety disorder might be related to an imbalance of the neurotransmitter serotonin. This is the first time the brain’s dopaminergic system was examined directly.

“Although there are no direct implications for treatment as a result of this study yet, it is another piece of evidence showing biological abnormalities, which may lead to new therapeutic approaches and insight into the origins of the disorder,” said Dr. van der Wee.
According to the National Institute of Mental Health, social anxiety disorder affects approximately 15 million American adults and is the third most common mental disorder in the United States, after depression and alcohol dependence. The essential feature of the disorder is the fear of being evaluated by others, with the expectation that such an assessment will be negative and embarrassing. It tends to run a chronic and unremitting course and often leads to the development of alcoholism and depression. The disorder most often surfaces in adolescence or early adulthood, but it can occur at any time, including childhood.
Co-authors of “Increased Serotonin and Dopamine Transporter Binding in Psychotropic Medication-Naïve Patients With Generalized Social Anxiety Disorder Shown by 123-I-_-(4-Iodophenyl)-Tropane SPECT” include J. Frederieke van Veen, Irene M. van Vliet, Herman G. Westenberg, Department of Psychiatry; and Henk Stevens, Peter P. van Rijk, Department of Nuclear Medicine, all from the Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands.

For more information: www.snm.org

Related Content

Siemens Healthineers Announces FDA Clearance of syngo.via VB30 Molecular Imaging Software
Technology | Nuclear Imaging | July 16, 2018
At the 2018 Annual Meeting of the Society of Nuclear Medicine and Molecular Imaging (SNMMI), June 23-26 in Philadelphia...
Cardiac MRI being performed at the DeBakey Heart Hospital.

Cardiac MRI being performed at the DeBakey Heart Hospital.

Feature | Cardiac Imaging | May 03, 2018 | By Jeff Zagoudis
Magnetic resonance imaging (MRI) for cardiac assessment provides a radiation-free alternative to other commonly used...
The Chalk River nuclear reactor license has been renewed, but will be decommissioned by 2028.

The Chalk River nuclear isotope reactor license has been renewed, but will be decommissioned by 2028. The reactor supplies about 50 percent of the world's supply of Tc99m.

Feature | Nuclear Imaging | April 02, 2018 | Dave Fornell
April 2, 2018 – The Canadian Nuclear Safety Commission (CNSC) announced March 29 that it renewed Canadian Nuclear Lab
A Tc99m SPECT cardiac exam showing myocardial perfusion in the heart.

Technetium-99m is primarily used for the detection of cancer and to assess perfusion defects in the heart caused by heart attacks or other conditions.

Feature | Radiopharmaceuticals and Tracers | February 08, 2018 | Dave Fornell
February 8, 2018 — The U.S.
Videos | Nuclear Imaging | August 24, 2017
Prem Soman, M.D., director of nuclear cardiology at the Heart and Vascular Institute, University of Pittsburgh, and p
GE Healthcare SPECT/CT and PET/CT Systems Enhance Personalized Patient Care
News | Nuclear Imaging | June 10, 2017
GE Healthcare showcased positron emission tomography (PET) and single photon emission computed tomography/computed...
advanced visualization
News | Molecular Imaging | June 09, 2017
The Food and Drug Administration (FDA) has cleared syngo.via VB20 for Molecular Imaging (MI) from Siemens Healthineers...
News | SPECT-CT | June 08, 2017
Siemens Healthineers debuts Symbia Intevo Bold at the 2017 annual meeting of the Society of Nuclear Medicine &...
Videos | Nuclear Imaging | April 28, 2017
David Wolinsky, M.D., director of nuclear cardiology at Cleveland Clinic Florida and past-president of the American S
xSPECT Quant technology, SPECT/CT, Symbia Intevo, Siemens Healthineers, RSNA 2016
News | SPECT Imaging | December 06, 2016
December 6, 2016 — At the 102nd Scientific Assembly and Annual Meeting of the Radiological Society of North America (
Overlay Init