Social phobia, a type of anxiety disorder, is characterized by persistent fear of one or more social or performance situations in which the person is exposed to unfamiliar people or to possible scrutiny by others (1). The individual fears that he or she will act in a way (or show anxiety symptoms) that will be embarrassing and humiliating. Exposure to the feared situation almost invariably provokes anxiety, which may take the form of a situationally bound or situationally pre-disposed Panic Attack. The person recognizes that this fear is unreasonable or excessive. The feared situations are avoided or else are endured with intense anxiety and distress. The avoidance, anxious anticipation, or distress in the feared social or performance situation(s) interferes significantly with the person’s normal routine, occupational (academic) functioning, or social activities or relationships, or there is marked distress about having the phobia. The mechanisms underlying the symptoms of social phobia are believed to be early negative life experiences along with maladaptive parenting styles leading to cognitive distortion, a shy and perfectionistic personality, in combination with genetic vulnerability, sympathetic hypersensitivity and autonomic dysregulation.
Genetic factors in Social Phobia
Some genetic factors that have been linked to social phobia are the serotonin transported linked polymorphic region (5HTTLPR) genotype and polymorphisms in the Brain Derived Neurotrophic Factor (BDNF) gene. The fewer the number of high-risk alleles, the better the response of social anxiety symptoms to selective serotonin re-uptake inhibitors (SSRI) (2). Also, blushing propensity, which as an intermediate phenotype of social anxiety disorder is considered to be more precisely defined than the overall categorical disease phenotype and closer to the underlying genotype, has been linked to 5-HTTLPR/5-HTT rs25531 haplotypes that are associated with reduced function of the serotonin transporter and consequently, less serotonin at the synapse (3). The role of BDNF in social phobia is a focus of current research in Korea. BDNF is the most abundant neurotrophin in the brain, acts on the hippocampus, basal forebrain, and frontal cortex, plays an important role in neuronal growth and differentiation during development and contributes to the survival, function, and plasticity of neurons in adulthood. Associations between a variety of psychiatric disorders and the BDNF Val66Met polymorphism have been found (4), including social phobia. (5)
The Autonomic System in Social Phobia
Prolonged social phobia is associated with an increase in QT dispersion. This association may result from prolonged anxiety and, in turn, a decrease in vagal modulation and/or increase in sympathetic modulation. Electrocardiographic Data showed that in Patients with Social Phobia and Normal controls normal subjects had lesser QT Dispersion and corrected rate QT dispersion. RR and HR didn’t significantly vary, in patients with Social Phobia Generalized Type showed less QT Dispersion than the patients with Social Phobia of Non-Generalized Type. (6)
Neuropsychological Study on SAD
Difference in the perception of six basic facial emotional expressions and neutral face using Ekman study analysis on 32 social phobia and 20 healthy controls and Children with social phobia had significantly poorer facial recognition skills than normal controls and reported greater anxiety upon completion of the recognition task. Social phobia patients exhibited increased timeout numbers, reaction and total time. The ability to correctly recognize facial expressions was decreased in social phobia patients compared to healthy subjects.The central effect of Oxytocin is said to play key role in social recognition, pair bonding, anxiety and maternal behaviours. Behaviour therapy and oxytocin stimulation has a positive feedback on Social Approach Behaviour, but the Social Anxiety governs it with a short leash. Another study shows that the administration of oxytocin improves mental representations of self, following exposure therapy. The increase rate of oxytocin was correlated with decrease rate of LSAS avoidance subscale score, however does not correlated with decrease rate of LSAS fear subscale score. No correlation between plasma oxytocin concentration and LSAS total score (or subscale scores). Low possibility as a state marker of SAD, Plasma oxytocin level was not associated with the scores of other scales for measuring anxiety (ASI, ST/IL HAM-A) or depression (MADRS) among the patients with SAD.
Pharmacotherapy approach and their effect
Pharmacotherapy of social phobia includes Selective serotonin reuptake inhibitor (SSRI), Reversible inhibitor of MAO-A (RIMA), Benzodiazepines and Beta-adrenergic receptor blockers. Treatment duration is important factor that can significantly predict the response. When comparing treatment adherence between SSRIs and RIMA (moclobemide) in patients with social phobia, the cumulative surviving proportions were significantly different between the SSRIs and moclobemide group at week 48 and week 96 (relatively late phase of treatment). When it comes to adherence the overall all-cause discontinuation rates were significantly lower with SSRIs than moclobemide (7). In conclusion, when the effect size of different modalities was compared, Combination therapy (SSRI+CBT) was most effective among three modalities, but there were no significant differences.
3. Domschke K, Stevens S, Beck B, Baffa A, Hohoff C, Deckert J, & Gerlach AL (2009). Blushing propensity in social anxiety disorder: influence of serotonin transporter gene variation. Journal of neural transmission (Vienna, Austria : 1996), 116 (6), 663-6 PMID: 18629430
4. Rybakowski JK (2008). BDNF gene: functional Val66Met polymorphism in mood disorders and schizophrenia. Pharmacogenomics, 9 (11), 1589-93 PMID: 19018714
5. Xie B, Wang B, Suo P, Kou C, Wang J, Meng X, Cheng L, Ma X, & Yu Y (2011). Genetic association between BDNF gene polymorphisms and phobic disorders: a case-control study among mainland Han Chinese. Journal of affective disorders, 132 (1-2), 239-42 PMID: 21295349
6. Nahshoni E, Gur S, Marom S, Levin JB, Weizman A, & Hermesh H (2004). QT dispersion in patients with social phobia. Journal of affective disorders, 78 (1), 21-6 PMID: 14672793
7. Ha J, Lim SW, Shin YC, & Oh KS (2011). Comparison of anxiety-related traits between generalized and nongeneralized subtypes of social anxiety disorder. The Journal of nervous and mental disease, 199 (6), 390-3 PMID: 21629017