Depression Anxiety Stress Scales – Short Form (DASS-21)

Abstract

The Depression Anxiety Stress Scales – Short Form (DASS-21) is an efficient, 21-item version of the original 42-item DASS. This self-report scale is designed to quantitatively measure the severity of three distinct negative emotional states: Depression, Anxiety, and Stress. The three subscales exhibit high internal consistency and provide meaningful discrimination between the constructs, making the DASS-21 a valuable instrument for both clinical practitioners and researchers. It is widely used to assess an individual’s current psychological state and monitor changes in affect throughout the course of treatment.

Keywords

DASS-21, DASS-42, Depression, Anxiety, Stress, psychological assessment, self-report, emotional states, psychopathology, clinical psychology.

Authors

S.H. Lovibond, P.F. Lovibond

Purpose

The primary purpose of the DASS-21 is to provide a rapid, quantitative assessment of symptomatic distress across the dimensions of Depression, Anxiety, and Stress. It aims to capture the affective experience of the respondent over the preceding week, offering a snapshot of their psychological state.

By yielding separate scores for each of the three scales, the instrument allows clinicians to identify the dominant negative emotional components present in an individual’s presentation, which is essential for targeted intervention planning. It is particularly useful for measuring state change over time in response to therapeutic or environmental factors.

Construct

The DASS-21 measures three distinct, yet correlated, dimensions of negative affect: Depression (characterized by low positive affect, anhedonia, and low self-esteem), Anxiety (characterized by autonomic arousal, skeletal muscle effects, and subjective experience of anxious affect), and Stress (characterized by non-specific arousal, difficulty relaxing, irritability, and impatience).

The scale operates under a dimensional conception of psychopathology, viewing emotional disturbance as continuous severity rather than discrete, categorical diagnoses. This dimensional approach provides a more nuanced understanding of psychological distress than traditional categorical models.

Validity

The DASS-21 was developed based on extensive data, including a large initial sample of 950 first-year university students, with 504 resulting sets used for scale refinement. Subsequent validation procedures involved checking the scores against established clinical outpatient groups diagnosed with anxiety, depression, and other mental disorders, confirming the scale’s capacity for clinical discrimination.

The scale demonstrates strong concurrent validity, aligning well with other measures of similar constructs (Antony et al., 1998). Furthermore, the interpretability of the DASS-21 is supported by robust normative data established by Henry and Crawford (2005), derived from a large non-clinical community sample (N=1794).

Reliability

The DASS-21 is reported to possess acceptable to excellent levels of internal consistency, consistent with the high psychometric properties of the original DASS-42. High internal consistency indicates that the items within each of the three subscales reliably measure their intended construct (e.g., all seven Depression items measure depression symptoms cohesively).

The consistent reliability ensures that the instrument is suitable for measuring clinical change, providing confidence that observed score differences over time reflect genuine changes in the respondent’s emotional state rather than measurement error.

Factor Analysis

The DASS-21 is structured on a three-factor model, corresponding directly to the Depression, Anxiety, and Stress subscales. This factor structure is strongly supported by research, which confirms that these three factors are statistically distinct, providing discriminant validity necessary to separate symptoms that might otherwise be confounded in older scales.

The clear differentiation achieved through factor analysis allows the DASS-21 to pinpoint specific areas of distress, contributing significantly to its utility in both research settings focused on the structure of negative affect and clinical settings requiring precise symptomatic measurement.

Instrument

Test Type: Psychometric Self-Report Questionnaire

Format: 21 items rated on a 4-point Likert scale (0 to 3).

Language Available: English (and numerous translations globally).

Population Group: Clinical and Non-Clinical settings.

Age Group: Suitable for individuals 17 years and older, with evidence supporting comparative use for ages as young as 12.

Population Details: Normative data based on a large community sample of 1794 non-clinical adults, validated against clinical outpatient groups suffering from various mental disorders.

Test Methodology: Respondents rate statements based on how much they applied to them over the past week. Raw subscale scores are calculated, multiplied by two (to maintain consistency with the DASS-42), and categorized into five severity ranges: normal, mild, moderate, severe, and extremely severe. Interpretation relies on dimensional percentiles derived from the non-clinical sample.

Keywords

Affective states, clinical screening, psychological distress, concurrent validity, normative data, S.H. Lovibond, P.F. Lovibond, emotional regulation.

Authors

Author ORCID Identifier: Not provided in source.

Affiliation Email addresses: Not provided in source.

Correspondence Address: The Psychology Foundation, Room 1005 Mathews Building, University of New South Wales, NSW 2052, Australia.

Permissions & Fee and Test Year

The DASS scales were developed by Lovibond and Lovibond and published in 1995 (2nd edition of the Manual). The scales themselves are generally available for free, non-commercial use by researchers and clinicians. However, full interpretive information and scoring instructions require the purchase of the official DASS Manual. The manual can be purchased via the official source: http://www2.psy.unsw.edu.au/groups/dass/order.htm.

Reference’s

Antony, M. M., Bieling, P. J., Cox, B. J., Enns, M. W., & Swinson, R. P. (1998). Psychometric properties of the 42-item and 21-item versions of the Depression Anxiety Stress Scales in clinical groups and a community sample. Psychological Assessment, 10(2), 176.

Henry, J. D., & Crawford, J. R. (2005). The short‐form version of the Depression Anxiety Stress Scales (DASS‐21): Construct validity and normative data in a large non‐clinical sample. British Journal of Clinical Psychology, 44(2), 227-239.

Lovibond, S.H.; Lovibond, P.F. (1995). Manual for the Depression Anxiety Stress Scales (2nd ed.). Sydney: Psychology Foundation.

Items of the Depression Anxiety Stress Scales – Short Form (DASS-21)

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

Instructions:

Please read each statement and press a response that indicates how much the statement applied to you over the past week. There are no right or wrong answers. Do not spend too much time on any statement.