Social anxiety disorder (SAD) refers to an anxiety disorder triggered by social situations. People with SAD have symptoms like fast heartbeat, sweating, and stomach upset when they are anxious. They have a fear that people might scrutinize their performance and evaluate them negatively.

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The main causes of SAD are past negative experiences, a new job, and genetic inheritance. SAD often occurs during the stage of early adolescence. This anxiety disorder can be inherited from parents.

Risk of genetic inheritance

A gene is a unit of heredity that gets transferred from the parents to their child or offspring and helps to determine their traits. A recent study was conducted on 1053 parents who were affected by SAD. After thorough analysis, it was concluded that there is a risk of developing SAD for 5 years in the early adolescence stage.

They identified three groups of parents whose offspring were at the risk of getting the disorder. The first group consisted of parents who were not diagnosed with any mental disorder in their lifetime, while the second group had parents who were diagnosed with some mental disorders other than social phobia and the third group included parents who had completed diagnosis of the disorder.

Children of parents who fulfilled the diagnostic criteria of SAD were found to be at a greater risk of developing SAD. The disorder was influenced by the family environment; an adverse atmosphere from inside the family during the developmental stages of a child can contribute to this disorder.

A few other genetics studies were carried out to address the same issue and the researchers were able to find more risk factors associated with hereditary social anxiety.

• A study has found the shyness or the social anxiety of the children may be correlated with the shyness of the biological mother
• When learning the behavior of their parents who have SAD, children most probably develop anxiety disorders
• The rate of occurrence of SAD is higher in both members of a set of monozygotic (genetically identical) twins than in dizygotic (fraternal) twins according to the data collected from a research on a sample of 2163 female twins with anxiety

Risk from gene polymorphism

A number of genes can contribute to SAD:

SLC6A4 gene

SLC6A4 is a serotonin transporter. There is a strong link between SLC6A4 and the chance of developing SAD.  Researchers have demonstrated that within the SLC6A4 gene, single nucleotide polymorphisms (SNP) are responsible for the development of SAD. SLC6A4 is also known as SERT or 5-HTT (5-hydroxytryptamine). Social anxiety disorder may be caused by defect in serotonin processing.

The neurotransmitter serotonin plays an important role in mood. If there is a block of neurotransmitter release, serotonin can become unbalanced, contributing to anxiety disorder and other conditions like depression.

ADRB1 gene

• g, The ADRB1 gene, or beta-1 adrenergic receptor (β1 adrenoreceptor), may play a role in SAD There is no conclusive proof of how this gene causes social anxiety.

CRF receptor gene

• Corticotropin-releasing factor (CRF) is one of the genes present in the CRF receptor in CRHR2. A mutation in CRHR2 causes social anxiety. The mutated CRHR2 gene disrupts binding between the CRF2 receptor and CRF, which is essential for stress reduction.

The RGS2 gene also contributes to SAD. As mentioned above, the genes that cause SAD have not yet been fully explored.

Treatment

The ratio of glutamate to creatine is as high as 13.2% in patients with SAD when compared with normal people. Monoamine oxidase inhibitors, selective serotonin-reuptake inhibitors (SSRIs), and serotonin–norepinephrine reuptake inhibitors (SNRIs) are found to be effective in treating SAD. The symptoms of SAD and abnormalities in brain, such as high amygdala activity, can be reversed using SSRIs.