Mild to severe social fears: ranking types of feared social situations using item response theory.

Social anxiety disorder is one of the most common mental disorders, and is associated with long term impairment, distress and vulnerability to secondary disorders. Certain types of social fears are more common than others, with public speaking fears typically the most prevalent in epidemiological surveys. The distinction between performance- and interaction-based fears has been the focus of long-standing debate in the literature, with evidence performance-based fears may reflect more mild presentations of social anxiety. This study aims to explicitly test whether different types of social fears differ in underlying social anxiety severity using item response theory techniques. Different types of social fears were assessed using items from three different structured diagnostic interviews in four different epidemiological surveys in the United States (n=2261, n=5411) and Australia (n=1845, n=1497); and ranked using 2-parameter logistic item response theory models. Overall, patterns of underlying severity indicated by different fears were consistent across the four samples with items functioning across a range of social anxiety. Public performance fears and speaking at meetings/classes indicated the lowest levels of social anxiety, with increasing severity indicated by situations such as being assertive or attending parties. Fears of using public bathrooms or eating, drinking or writing in public reflected the highest levels of social anxiety. Understanding differences in the underlying severity of different types of social fears has important implications for the underlying structure of social anxiety, and may also enhance the delivery of social anxiety treatment at a population level.