A depressive symptom scale for the California Psychological Inventory: construct validation of the CPI-D

To facilitate life span research on depressive symptomatology, a depressive symptom scale for the California Psychological Inventory (CPI) is needed. The authors constructed such a scale (the CPI-D) and compared its psychometric properties with 2 widely used self-report depression scales: the Beck Depression Inventory and the Center for Epidemiological Studies Depression Scale. Construct validity of the CPI-D was examined in 3 studies. Study 1 established content validity, classifying CPI-D items into Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition depressive symptoms. Study 2 used 3 large samples to gather evidence for reliability and validity: correlational analyses demonstrated alpha reliability and convergent and discriminant validity; factor analysis provided evidence for discriminant validity with anxiety; and regression analyses demonstrated comparative validity with existing standard PI scales. Study 3 used clinician ratings of depression and anxiety as criteria for external validity.