Psychometric properties of the 21-item Depression Anxiety Stress Scale (DASS-21)

Abstract

Depression, anxiety and stress are recognised as global public health problems especially in developing countries. Early detection of these disorders is essential to provide psychological interventions for individuals experiencing these negative emotional conditions. This study determined the Nigerian psychometric properties for the 21-item version of the depression, anxiety and stress scale among a sample of medical students. Two hundred and forty medical students from the Lagos State University College of Medicine, Lagos, Nigeria completed the depression anxiety and stress scale, state trait anxiety inventory and self-rating depression scale. The reliability, discriminative, concurrent and convergent properties were determined. The reliability of DASS-21 showed that it has excellent Cronbach’s alpha values of 0.81, 0.89 and 0.78 for the subscales of depressive, anxiety and stress respectively. It was found to have excellent internal consistency, discriminative, concurrent and convergent validities. The depression and anxiety subscales of DASS-21 had good correlations with self-rating depression scale and state trait anxiety inventory. The DASS-21 was found to have  commendable psychometric properties. It is reliable, valid and easy to administer. Its utility by clinicians will enhance the diagnoses of depression, anxiety and stress among university students.

Keywords: DASS-21, depression, anxiety, Stress, psychometric properties, Lagos, Nigeria