Psychometric Properties of the Social Interaction Anxiety Scale (SIAS) and the Social Phobia Scale (SPS) Variants in Turkish Clinical and General Population Samples.

The current study aimed to adapt and validate the Turkish versions of the Social Interaction Anxiety Scale (SIAS), Social Phobia Scale (SPS), Straightforwardly Worded Social Interaction Anxiety Scale (S-SIAS), and their short forms (SIAS-6, SPS-6). Given the scarcity of reliable and valid instruments for measuring social anxiety in Türkiye, the adaptation of these scales aims to address a critical gap in the assessment tools available for this population. We examined the psychometric properties of the scales in participants diagnosed with social anxiety disorder (n = 36; 50% female) and in a general population sample (n = 487; 73.92% female). Confirmatory factor analyses (CFA) confirmed the original factor structures of the SIAS and SPS, with the SIAS-6 and SPS-6 showing the best fit statistics. Moreover, reliability analyses indicated excellent internal consistency for both scales and their short forms. Convergent validity was supported by significant correlations between the SIAS, SPS, and the Depression Anxiety Stress Scales-21 (DASS-21) subscales, as well as the Brief Fear of Negative Evaluation Scale (BFNES). Item response theory (IRT) analyses further highlighted the discriminative power of the items, while receiver operating characteristic (ROC) analyses indicated that the short forms maintain robust sensitivity and specificity comparable to the full versions. Overall, the Turkish versions of the SIAS, SPS, and their short forms demonstrated strong psychometric properties, supporting their use in both clinical and research settings.