Psychometric properties of the Center for Epidemiologic Studies-Depression scale in multiple sclerosis

The factorial structure of the Center for Epidemiologic Studies-Depression (CES-D) scale has been examined on a large sample of multiple sclerosis (MS) subjects (n = 696), general practice patients (n = 1,308) and healthy workers (n = 342). The aim of this study was to verify if the CES-D is a valid and reliable scale to assess depressive symptomatology in MS. As previously reported in the literature, we found four factors that measure depressed affect, positive affect, somatic complaints or retarded activity and interpersonal relationships. The percent of total variance explained by the four factors was greater than 50% in each group. Cronbach's alpha coefficients were 0.90 in the MS sample and 0.93 in the general practice sample, indicative of high reliability in both samples. From these results, we conclude that the CES-D can be used to screen for depression in epidemiological studies of this psychiatric disorder among MS patients.