Discriminant validity of the SCL-90 dimensions of anxiety and depression.

Although the SCL-90 and other self-report measures of anxiety and depression have long been criticized for inadequate factor structure and unacceptably high correlations with each other, recent evidence indicates the use of homogeneous samples results in greatly improved discriminant validity. This study utilized homogeneous samples of anxious (N = 54) or depressed (N = 120) outpatients and a factor analysis was conducted on their responses to the depression and anxiety items on the SCL-90. Clearly separate factors for anxiety and depression emerged. Results are discussed with respect to implication for measures of depression and anxiety.