Dopamine-Serotonin Balance Could Be Previously Unknown Factor for Social Anxiety

It long been known that certain neurotransmitter systems show clear differences in the brains of people with psychiatric disorders compared to controls. But new findings from Uppsala University suggest that the balance between two neurotransmitters, serotonin and dopamine, may be a better predictor of social anxiety than changes in either system individually.

The results are published in Molecular Psychiatry.

“We see that there is a different balance between serotonin and dopamine transport in people with social anxiety disorder compared with control subjects. The interaction between serotonin and dopamine transport explained more of the difference between the groups than each carrier individually. This suggests one should not focus exclusively on one signal substance at a time, the balance between different systems may be more important,” says Olof Hjorth, Ph.D. student at the Department of Psychology at Uppsala University, Sweden.

Social anxiety can be a highly debilitating psychiatric disorder with negative impacts on the individual’s relationships and working life. This study shows that affected people may have an imbalance between the serotonin and dopamine transporters in the amygdala and other brain areas that are important for fear, motivation and social behavior. The functioning of the brain’s signal substances is affected by the amount of reuptake by the transmitter cell, which is controlled by specific transporter proteins.

“Previously, we have found an increased production and altered reuptake of serotonin in sufferers of social anxiety disorder, a finding we now, in part, replicate,” says Hjorth. He adds, “We can now show that dopamine reuptake is also directly related to the severity of the social anxiety symptoms that the individual is experiencing.”

The method used in the study is called positron emission tomography (PET), in which radioactive agents, injected into the blood stream, decay and release a signal that allows the scientists to determine the density of available transporter proteins in different areas of the brain.

Social anxiety can be a highly debilitating psychiatric disorder with negative impacts on the individual’s relationships and working life. Image is in the public domain.

The researchers hope that the current findings can lead to a better understanding of the causes of social anxiety and ultimately to new, more effective treatments.

“Many of the patients we meet have symptoms that affect all parts of their everyday life, and many of them have suffered for most of their lives, so understanding the cause and finding effective treatments are our highest priority,” says Hjorth.

Reference: Hjorth, O. R., Frick, A., Gingnell, M., Hoppe, J. M., Faria, V., Hultberg, S., Alaie, I., Månsson, K. N. T., Wahlstedt, K., Jonasson, M., Lubberink, M., Antoni, G., Fredrikson, M., & Furmark, T. (2019). Expression and co-expression of serotonin and dopamine transporters in social anxiety disorder: a multitracer positron emission tomography study. Molecular Psychiatry, 1–10. https://doi.org/10.1038/s41380-019-0618-7

This article has been republished from materials provided by Uppsala University. Note: material may have been edited for length and content. For further information, please contact the cited source.