The authors critically surveyed several preclinical and clinical neurobiological models of social …

• Abstract
• Introduction
• Models Relevant to Social Anxiety
• Neurodevelopmental Issues
• Genetics of Social Anxiety Disorder
• Clinical Neurobiology of Social Phobia
• Neuroimaging
• Conclusions
• Footnotes
• References
• Table
• Appendix

Biology Articles » Neurobiology » Neurobiology of Diseases & Aging » Neurobiological Mechanisms of Social Anxiety Disorder » Genetics of Social Anxiety Disorder

Genetics of Social Anxiety Disorder

- Neurobiological Mechanisms of Social Anxiety Disorder

Although there is increasing evidence that social anxiety disorder and its childhood variants, including behavioral inhibition and shyness, have a strong familial basis, the genetics of the disorder have not been adequately studied. Several early studies (58, 59) established a familial link, but only for the generalized subtype (59). It was reported that if a proband has a diagnosis of social anxiety disorder, the percentage of first-degree relatives with the illness was 15%, which was greater than the 10% finding in subjects with agoraphobia and less than the 31% seen in subjects with simple phobia (49). Subsequently, a larger study (60) showed that the generalized subtype was markedly increased in frequency (approximately 10 times greater) among first-degree relatives of generalized social phobic probands. Another study (61) demonstrated that the children of patients with social anxiety disorder were at an increased risk of developing this disorder and other anxiety disorders.

The low genetic concordance rates for social anxiety disorder in monozygotic twins (62) have suggested that genetics plays a limited role in its development. As we suggested for panic disorder (1), what appears to be inherited is a susceptibility to social anxiety, not the disorder itself. Although no systematic genetic linkage studies employing a genomic scan or search among candidate genes have been conducted for social anxiety disorder so far, such studies are underway for panic disorder (63) and OCD (64). Likewise, molecular genetic studies of candidate genes for the several neurotransmitter systems implicated in social anxiety, notably the serotonin transporter and dopamine receptor and their various subtypes, have allowed for associations between specific genes and behavioral traits, such as harm avoidance and novelty seeking (65, 66)—characteristics relevant to the social anxiety disorder phenotype. Thus, genetic and family studies in social anxiety disorder are still in their infancy but support longitudinal clinical data that are suggestive of links between childhood and adult variants of the disorder.