The 21-item DASS is a set of three self-report scales designed to measure the emotional states of depression, anxiety and stress. A 4-point severity scale measures the extent to which each state has been experienced over the past week (7 days). Each of the three DASS-21 scales contains seven items, divided into subscales with similar content. The depression scale assesses dysphoria, hopelessness, devaluation of life, self-deprecation, lack of interest/involvement, anhedonia and inertia. The anxiety scale assesses autonomic arousal, skeletal muscle effects, situational anxiety, and subjective experience of anxious affect. The stress scale is sensitive to levels of chronic non- specific arousal. It assesses difficulty relaxing, nervous arousal, and being easily upset/agitated, irritable/over-reactive, and impatient. Scores for depression, anxiety, and stress are calculated by summing the scores for the relevant items.
The DASS has good test-retest reliability, high internal consistency, and adequate convergent and discriminant validity with other measures of anxiety and depression (Antony et al., 1998; Brown, Chorpita, Korotitsch, & Barlow, 1997). Little overlap has been found between the three subscales, which is consistent with the tripartite model (Clark & Watson, 1991) upon which the DASS is based. Brown and colleagues (1997) found the depression scale to be most strongly correlated with measures of depression and positive affect, the anxiety scale to be most strongly correlated with measures of physiological arousal and panic, and the stress scale to be most strongly correlated with measures of worry and negative affect than the other two scales.