This study evaluated psychometric properties of the Patient Health Questionnaire-9 (PHQ-9), the Center for Epidemiological Studies Depression Scale-10 (CESD-10), and the 8-item PROMIS Depression Short Form (PROMIS-D-8; 8b short form) in a sample of individuals living with multiple sclerosis (MS).Research Method:
Data were collected by a self-reported mailed survey of a community sample of people living with MS (n = 455). Factor structure, interitem reliability, convergent/discriminant validity and assignment to categories of depression severity were examined.Results:
A 1-factor, confirmatory factor analytic model had adequate fit for all instruments. Scores on the depression scales were more highly correlated with one another than with scores on measures of pain, sleep disturbance, and fatigue. The CESD-10 categorized about 37% of participants as having significant depressive symptoms. At least moderate depression was indicated for 24% of participants by PHQ-9. PROMIS-D-8 identified 19% of participants as having at least moderate depressive symptoms and about 7% having at least moderately severe depression. None of the examined scales had ceiling effects, but the PROMIS-D-8 had a floor effect.Conclusions:
Overall, scores on all 3 scales demonstrated essential unidimensionality and had acceptable interitem reliability and convergent/discriminant validity. Researchers and clinicians can choose any of these scales to measure depressive symptoms in individuals living with MS. The PHQ-9 offers validated cutoff scores for diagnosing clinical depression. The PROMIS-D-8 measure minimizes the impact of somatic features on the assessment of depression and allows for flexible administration, including Computerize Adaptive Testing (CAT). The CESD-10 measures 2 aspects of depression, depressed mood and lack of positive affect, while still providing an interpretable total score.