Investigating the Factor Structure of the Kessler Psychological Distress Scale in Community and Clinical Samples of the Australian Population

The Kessler 10 Psychological Distress Scale (K10) is a brief dimensional scale designed to measure and monitor trends of psychological distress. Recently the scale has been utilised by general practitioners and clinicians to screen for common mental disorders and measure treatment outcomes. Despite the K10 demonstrating a sound one dimensional structure in the general population, the scale's structure has yet to be comprehensively tested in clinical samples. The current study aimed to use confirmatory factor analysis to test three theoretical structure models of the K10 and one model for the K6 (a six item variant) in a sample from a tertiary referral clinic for mood and anxiety disorders and compare those results with a population sample from the Australian National Survey of Mental Health and Wellbeing. The results demonstrated that a two factor model with correlated latent factors representing depression and anxiety fit the clinical sample the best whilst a one factor model with correlated errors between several items fit the population sample the best. The results are discussed further in relation to scoring and interpreting the Kessler scales.