Is “relationship fear” unique to Japan? Symptom factors and patient clusters of social anxiety disorder among the Japanese clinical population

Abstract Background There have been only a limited number of cross-cultural studies of social anxiety disorder (SAD), especially as diagnosed with modern operationalized diagnostic criteria and as measured with recently developed assessment instruments. We examined the symptomatological structure and clinical subtypes of patients with DSM-IV SAD among the Japanese clinical population. Methods We performed confirmatory and exploratory factor analyses of the joint Social Interaction Anxiety Scale and Social Phobia Scale [Mattick, R.P., Clarke, J.C., 1998. Development and validation of measures of social phobia scrutiny fear and social interaction anxiety. Behav. Res. Ther. 36, 455–470.] from 149 psychiatric patients diagnosed with SAD. Based on the derived symptom factors, we further ran cluster analysis to identify patient subgroups. Results Factor analyses revealed three factors which were named “scrutiny fears”, “conversation fears” and “relationship fears”. The first two appeared common to Western clinical populations but the third appeared unique to the Japanese. Cluster analysis based on these three factor scores yielded three subgroups, which were externally validated and which overall corresponded with mild, moderate and pervasive subtypes of social phobia. Limitations Both factor analysis and cluster analysis employed in the present study are exploratory in nature. Further empirical examination in different settings and cultures is necessary to provide definitive answers. Conclusions It is suggested that we may need three symptom subscales and three subtypes in order to better account for cultural variations in the presentation of SAD.