Screening for psychiatric disorders with the Patient Health Questionnaire (PHQ). Results from the German validation study

The aim of this study was to validate the German version of the Patient Health Questionnaire (PHQ). The PHQ has been developed to screen for mental disorders in primary care, using diagnostic criteria from the DSM-IV. Three hundred and fifty-seven medical outpatients and 171 psychosomatic outpatients completed the PHQ and the Structured Clinical Interview for DSM-IV (SCID), the latter serving as criterion standard. Acceptability of the PHQ as the screening instrument was investigated for physicians and patients. For the diagnosis of major depressive disorder, the PHQ showed excellent criterion validity (medical patients: sensitivity, 95%; specificity, 86%). Good operating characteristics were also found for the diagnosis of panic disorder. The use of the PHQ was well accepted by more than 90% of both physicians and patients. Overall. the PHQ is a valid, effective, and well accepted diagnostic tool for use in research and clinical practice. Its' application in primary care and other clinical settings might contribute to better diagnosis and treatment of mental disorders.