Hippocampus and amygdalar volumes in patients with social anxiety disorder

Social anxiety disorder (SAD) is a usual anxiety disorder characterized by being afraid of ashamed, humiliated and negative assessment by other persons in a society. It is known that anxiety originates from central nervous system. Limbic system includes thalamus, hypothalamus, hypocampus, pineal gland, hypophysis and amygdala which are neuroanatomic structures in subcortical area and is responsible for memory and mood changes. Anatomic and functional imaging techniques contributed to the better understanding etiology of psychiatric diseases and improvement of diagnostic approach. In our study, the purpose was to compare the volume changes of hypocampus and amygdala in SAD patients and healthy subjects. Twenty healthy and 15 patients with SAD were included in our study. The volume of hypocampus and amygdala in all patients was measured on MRI examinations. The mean volume of right hypocampus and left hypocampus in patient group were 3.47 ±0.57 cm3 and 3.04 ± 0.48 cm3, respectively. The mean volume of right hypocampus and left hypocampus in control group were 3.00±0.24 cm3 and 2.98 ± 0.27 cm3 , respectively. The right hypocampus volume of was significantly higher than control group (P < 0.05). There was no significant difference between left hypocampus volume of patient and control group (P>0.05). The amygdala volume of patient and control group was not significantly different (P>0.05). The correlation of amygdala in patient group was impaired . In conclusion, our study revealed abnormalities of amygdala and hypocampus which may be associated with physiopathology of SAD. Keywords: Social anxiety disorder, hypocampus, amygdala, MRI volume