Validity of four screening scales for major depression in MS

Background: There is a role for brief assessment instruments in detection and management of major depression in MS. However, candidate scales have rarely been validated against a validated diagnostic interview. In this study, we evaluated the performance of several candidate scales: Patient Health Questionnaire (PHQ)- 9, PHQ-2, Center for Epidemiologic Studies Depression rating scale (CES-D), and Hospital Anxiety and Depression Scale (HADS-D) in relation to the Structured Clinical Interview for DSM-IV (SCID). Methods: The sample was an unselected series of 152 patients attending a multiple sclerosis (MS) clinic. Participants completed the scales during a clinic visit or returned them by mail. The SCID was administered by telephone within two weeks. The diagnosis of major depressive episode, according to the SCID, was used as a reference standard. Receiver-operator curves (ROC) were fitted and indices of measurement accuracy were calculated. Results: All of the scales performed well, each having an area under the ROC > 90%. For example, the PHQ-9 had 95% sensitivity and 88.3% specificity when scored with a cut-point of 11. This cut-point achieved a 56% positive predictive value for major depression. Conclusions: While all of the scales performed well in terms of their sensitivity and specificity, the availability of the PHQ-9 in the public domain and its brevity may enhance the feasibility of its use.