Self-Report Measures, Screenings and Assessments
The Depression Anxiety Stress Scale (DASS-21)
THC Editorial Team January 24, 2022
- What Is the Depression Anxiety Stress Scale (DASS-21)?
- What Does the Depression Anxiety Stress Scale (DASS-21) Measure?
- Depression Anxiety Stress Scale (DASS-21) Scoring Guidelines
- Depression Anxiety Stress Scale (DASS-21) Validity and Reliability
What Is the Depression Anxiety Stress Scale (DASS-21)?
Developed by researchers Lovibond and Lovibond at the University of New South Wales, the Depression Anxiety Stress Scale (DASS-21) is a well-established, self-administered instrument with 21 statements that help people define, understand, and measure clinically significant emotional states.1The authors conceptualize this scale as a dimensional, rather than a categorical, measure of psychological disorder.
The World Health Organization (WHO) estimates that 4.4% of the global population is affected by depression, and 3.6% is affected by anxiety.2 In addition, 30% of individuals in the United States report that they are “always” or “often” under stress.2 Lovibond and Lovibond created the DASS-21 to efficiently detect depression, anxiety, and stress in the general population. The first iteration of the scale included 42 items, but the DASS-21 is a shorter, revised version that can be completed faster.2
What Does the Depression Anxiety Stress Scale (DASS-21) Measure?
This assessment tool contains three scales that separately measure the emotional states of depression, anxiety, and stress.
The depression scale measures general dissatisfaction, hopelessness, devaluation of life, self-criticism, lack of interest, inability to feel pleasure, and emotional states resistant to change (items 3, 5, 10, 13, 16, 17, and 21).3
The anxiety scale measures autonomic arousal, muscle effects, situational anxiety, and subjective beliefs regarding anxious affect (items 2, 4, 7, 9, 15, 19, and 20).3
The stress scale measures an individual’s level of relaxation, nervousness, irritability, agitation, overreactivity, and impatience (items 1, 6, 8, 11, 12, 14, and 18).3
Overall, this instrument measures the severity of symptoms on a scale from within normal limits to extremely severe.4
Depression Anxiety Stress Scale (DASS-21) Scoring Guidelines
Each of the 21 items is rated on a four-point Likert scale ranging from 0 to 3:5
0 – Did not apply to me at all
1 – Applied to me to some degree or some of the time
2 – Applied to me to a considerable degree or a good part of the time
3 – Applied to me very much or most of the time
The item scores on each scale are totaled and multiplied by 2 to obtain the three scale scores.1,3
The cutoff scores for severity labels are listed below:6
Depression Anxiety Stress Scale (DASS-21) Validity and Reliability
Researchers assess the reliability and validity of their work in order to evaluate the quality of their research. Reliability refers to how consistently reproducible the research results are, meaning if something is reliable, it is statistically consistent. Validity refers to how well the results measure what they are intended to measure, meaning if findings are valid, they are statistically accurate.7
The scales of the DASS-21 have been proven to have high internal consistency and high discriminative, concurrent, and convergent validity.4 In addition to being reliable and valid, the DASS-21 is straightforward to self-administer.8
The DASS-21 has been proven to be valid across numerous countries (Brazil, Canada, Hong Kong, Romania, Taiwan, Turkey, the United Arab Emirates, and the United States),9 nonclinical populations, clinical populations, and individuals who have experienced a traumatic injury.10
Although the DASS-21 is a reliable and valid instrument, individuals should not use this scale as a diagnostic tool. This scale is merely a self-reported survey that may help indicate whether an individual should seek psychological or psychiatric evaluation and help.