Oxytocin levels in social anxiety disorder.

Oxytocin is a neuropeptide recently associated with social behavior in animals and humans, but the study of its function in populations with social deficits such as autism, schizophrenia, and social anxiety disorder has only recently begun. We measured plasma oxytocin in 24 patients with Generalized Social Anxiety Disorder (GSAD) and 22 healthy controls using an enzyme-linked immunosorbent assay. There were no significant differences in oxytocin level (pg/mL) between patients (M=163.0, SD=109.4) and controls (M=145.0, SD=52.9, z=0.21, P=0.8). Within the GSAD sample, however, higher social anxiety symptom severity adjusted for age and gender was associated with higher oxytocin level (R2=0.21, beta=0.014, SE=0.006, t=2.18, P=0.04). In addition, dissatisfaction with social relationships was associated with higher oxytocin levels (R2=0.18, beta=-0.20, SE=0.10, t=-2.01, P=0.05). Our data provide preliminary support for a link between social anxiety severity and plasma oxytocin. These findings may suggest a possible role for oxytocin as a facilitator of social behavior, an effect which may not be fully utilized in individuals with severe social anxiety.