Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

Social phobia, and particularly the generalized subtype of social phobia, has been associated with dysfunction of the dopamine system. Evidence includes selectivity in response to pharmacotherapy, lower levels of homovanillic acid in cerebrospinal fluid, higher than expected comorbidity with Parkinson's Disease, and decreased dopamine transporter density. Subordinate social status in animals, which has been suggested to be relevant to social phobia in an evolutionary model of the disorder, has also been associated with decreased dopamine levels and low D2 receptor density. Our preliminary results of an IBZM-SPECT study suggest that dopamine D2 receptor density may also be decreased in persons with generalized social phobia. Mechanisms for the development of dopamine system dysfunction in social phobia remain unclear. Low D2 receptor density, for example, may represent a trait phenomenon of generalized hypofunction of the dopamine system, in which there are low levels of dopamine release, low levels of dopamine reuptake by the dopamine transporter, and low levels of post-synaptic dopaminergic transmission. An alternative model would conceptualize low D2 receptor density as a state of downregulation secondary to high levels of dopamine release, as has been observed acutely after social defeat in animals.

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Presentation Number SAschneier0682
Keywords: social phobia, anxiety disorders, dopamine, brain imaging, SPECT