Factor structure of the depression anxiety stress Scale-21 (DASS-21): Unidimensionality of the Arabic version among Egyptian drug users

Background Emotional distress is common among illicit drug users, and it can negatively affect treatment outcomes and increase the risk of relapse. Nonetheless, instruments that properly measure emotional distress are lacking. Therefore, this study investigated the factor structure of the Arabic Depression Anxiety Stress Scale-21 (DASS-21) in that population.