Severity of psychiatric disorder and the 30-item general health questionnaire.

The 30-item General Health Questionnaire misclassified 26 per cent of respondents in two samples of women who were interviewed by a psychiatrist using the Present State Examination. False negatives were likely to be women with chronic disorders, particularly anxiety states. False positives were likely to be distressed by severe physical illness, a recent adverse life event, or loneliness. Applying a higher threshold score to their GHQ responses would help to separate those with a diagnosable psychiatric disorder from those in states of distress.