The social anxiety spectrum

Social anxiety disorder is well suited to the spectrum concept because it has trait-like qualities of early onset, chronicity, and no empirically derived threshold that demarcates normal from clinically significant trait social anxiety. Strong evidence exists that at least some forms of shyness, avoidant personality disorder, and selective mutism lie on a social anxiety disorder spectrum. For several other disorders, including the atypical subtype of major depression, body dysmorphic disorder, and eating disorders, significant subgroups of patients seem to have features of social anxiety disorder. A growing body of evidence links behavioral inhibition to the unfamiliar to a social anxiety disorder spectrum with some specificity. Biologic measures of dopamine system hypoactivity have been linked to social anxiety disorder, trait detachment, and general deficits in reward and incentive function, and more research is needed to clarify which of these traits are most associated with these measures. Identification of conditions that may lie on a social anxiety disorder spectrum has clinical utility in the broader application of pharmacologic and cognitive-behavioral treatments of known efficacy for social anxiety disorder.