The factor structure, reliability, and validity of the Depression Anxiety Stress Scales (DASS; SH Lovibond & PF Lovibond, 1995) and the 21-item short form of these measures (DASS–21) were examined in nonclinical volunteers (n= 49) and patients with Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) diagnoses of panic disorder (n= 67), obsessive-compulsive disorder (n= 54), social phobia (n= 74), specific phobia (n= 17), and major depressive disorder (n= 46). This study replicates previous findings indicating that the DASS distinguishes well between features of depression, physical arousal, and psychological tension and agitation and extends these observations to the DASS–21. In addition, the internal consistency and concurrent validity of the DASS and DASS–21 were in the acceptable to excellent ranges. Mean scores for the various groups were similar to those in previous research, and in the expected direction. The implications of these findings are discussed.(PsycINFO Database Record (c) 2019 APA, all rights reserved)