Reliability, validity and clinical utility of a Japanese version of the Social Adaptation Self-evaluation Scale as calibrated using the Beck Depression Inventory

Aim: The Social Adaptation Self-evaluation Scale (SASS) was developed to assess the social impairment caused by depression. The purposes of this study were to develop a Japanese version of the SASS (SASS-J) and to evaluate its reliability and validity. Methods: The SASS-J and the 21-item Beck Depression Inventory (BDI) were administered to 322 participants (95 working patients who were working while under treatment for depression, 99 nonworking patients who were absent from their work due to depression, and 128 healthy controls). The healthy controls underwent both questionnaires twice, at baseline and 2 weeks later, in order to assess test-retest reliability. Results: Cronbach's alpha was 0.81. Significance correlations were found between SASS-J scores at baseline and 2 weeks later in healthy controls (R = 0.845, P < 0.001). There were negative correlations between the SASS-J and BDI scores (r = -0.683, P < 0.001). Mean SASS-J scores differed significantly among the three groups (working patients: 33.7 +/- 7.9; non-working patients: 25.2 +/- 7.8; healthy controls: 36.1 +/- 6.0 [mean +/- SD]). The best compromise between the true positive and the false negative rate in this study was at a cut-off point of 25/26. Conclusion: SASS-J showed sufficient reliability and validity, and could be considered a suitable instrument to evaluate social functioning in depressive patients.