Improving screening for mental disorders in the primary care setting by combining the GHQ-12 and SCL-90-R subscales

Most of patients with mental disorders are cared for in the primary care sector, rather than in the mental health sector. Self-report questionnaires can be used as screening instruments to identify mental disorders in primary care. The 12-item General Health Questionnaire (GHQ-12) is a widely used screening questionnaire for common mental disorders. Unfortunately, the GHQ-12 generates many false presumptive positives and forces the employer to expend resources on confirmatory testing. Therefore, the aim of the present report was to investigate a two-stage questionnaire screening design in a primary care setting. The GHQ-12 was used as an initial screening test followed by the Symptom Checklist (SCL-90-R). A randomly selected sample of adult outpatients (N = 408) from 18 primary care offices was screened using the two questionnaires. A structured diagnostic interview and an impairment rating were used as standards. Subjects were classified into true-positives and false-positives based on their GHQ-12 score and the clinical interview. Logistic regression and receiver operating characteristic analysis were performed to determine whether the SCL-90-R increased accuracy in screening for mental disorders by discriminating between true-positive and false-positive cases. The SCL-90-R subscales Depression, Obsessive-Compulsive, and Somatization were identified as factors associated with the GHQ-12 classification. Therefore, a significant improvement in screening performance of the GHQ-12 is obtained by combination of the test results. The approach may reduce artifact due to high scoring tendencies not associated with psychological disorder.