Validity of the Japanese version of the GHQ among antenatal clinic attendants.

The validity of the Japanese version of the 30-item General Health Questionnaire (GHQ) was examined against the semi-structured interview-based Research Diagnostic Criteria (RDC) as external criteria. The GHQ total score discriminated 'cases' and 'non-cases' satisfactorily but its recommended cut-off point was higher (7/8) than that of the original English version (4/5). Discriminant function analysis revealed that only 13 items contributed to the discriminatory power and that their discriminant function score was better than a simple summation of the 30 GHQ item scores in terms of validity.