DASS (psychology)
Encyclopedia
DASS, the Depression Anxiety Stress Scales, is made up of 42 self report items to be completed over five to ten minutes, each reflecting a negative emotional symptom . Each of these is rated on a four-point Likert scale
of frequency or severity of the participants' experiences over the last week with the intention of emphasising states over traits. These scores ranged from 0, meaning that the client believed the item "did not apply to them at all", to 3 meaning that the client considered the item to "apply to them very much, or most of the time". It is also stressed in the instructions that there are no right or wrong answers.
The sum of the relevant 14 items for each scale constitute the participants' scores for each of Depression
, Anxiety
and Stress, including items such as "I couldn't seem to experience any positive feeling at all", "I was aware of the dryness of my mouth" and "I found it hard to wind down" in the respective order of the scales. The order of the 42 items has been randomised so that items of the same scale are not clustered together. Each of the scales is then broken down into subscales comprising two to five items each. Depression has subscales assessing 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's subscales highlight levels of non-chronic arousal through difficulty relaxing, nervous arousal and being easily upset/agitated, irritable/over-reactive and impatient.
The main purpose of the DASS is to isolate and identify aspects of emotional disturbance; for example, to assess the degree of severity of the core symptoms of depression, anxiety or stress. The initial aims of the scale's constructions were to define the full range of core symptoms of depression and anxiety, meet rigorous standards of psychometric adequacy, and develop maximum discrimination between the depression anxiety scales. While the DASS can be administered and scored by individuals without psychology
qualifications, it is recommended that the interpretation and decisions based on results are made by an experienced clinician
in combination with other forms of assessment.
The Depression, Anxiety, and Stress Scales were developed by researchers at the University of New South Wales
(Australia
) .
The test was developed using a sample of responses from the comparison of 504 sets of results from a trial by students, taken from a larger sample of 950 first year university student responses.
The test was then normed
on a sample of 1044 males and 1870 females aged between 17 and 69 years, across participants of varying backgrounds, including university students, nurses in training and blue and white collared employees of a major airline, bank, railway workshop and naval dockyard. The scores were subsequently checked for validity against outpatient groups including patients suffering from anxiety and depressive disorders, insomnia
cs, myocardial infarction
patients, as well as patients undergoing treatment for sexual
, menopausal and depressive disorders. While the test was not normed against samples younger than 17, due to the simplicity of language, there has been no compelling evidence against the use of the scales for comparison against children as young as 12.
The reliability scores of the scales in terms of Cronbach's alpha
scores rate the Depression scale at 0.91, the Anxiety scale at 0.84 and the Stress scale at 0.90 in the normative sample. The mean
s and standard deviation
s for each scale are 6.34 and 6.97 for depression, 4.7 and 4.91 for anxiety and 10.11 and 7.91 for stress, respectively. The mean scores in the normative sample did vary slightly between genders as well as varying by age, though the threshold scores for classifications do not change by these variations. The Depression and Stress scales meet the standard threshold requirement of 0.9 for research, however, the Anxiety scale still meets the 0.7 threshold for clinical applications, and is still close to the 0.9 required for research.
Likert scale
A Likert scale is a psychometric scale commonly involved in research that employs questionnaires. It is the most widely used approach to scaling responses in survey research, such that the term is often used interchangeably with rating scale, or more accurately the Likert-type scale, even though...
of frequency or severity of the participants' experiences over the last week with the intention of emphasising states over traits. These scores ranged from 0, meaning that the client believed the item "did not apply to them at all", to 3 meaning that the client considered the item to "apply to them very much, or most of the time". It is also stressed in the instructions that there are no right or wrong answers.
The sum of the relevant 14 items for each scale constitute the participants' scores for each of Depression
Clinical depression
Major depressive disorder is a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and by loss of interest or pleasure in normally enjoyable activities...
, Anxiety
Anxiety
Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...
and Stress, including items such as "I couldn't seem to experience any positive feeling at all", "I was aware of the dryness of my mouth" and "I found it hard to wind down" in the respective order of the scales. The order of the 42 items has been randomised so that items of the same scale are not clustered together. Each of the scales is then broken down into subscales comprising two to five items each. Depression has subscales assessing dysphoria
Dysphoria
Dysphoria is medically recognized as a mental and emotional condition in which a person experiences intense feelings of depression, discontent and indifference to the world around them.Mood disorders can induce dysphoria, often with a heightened risk of suicide, especially in...
, hopelessness, devaluation of life, self-deprecation
Self-deprecation
Self-deprecation, or Self-depreciation, is the act of belittling or undervaluing oneself. It can be used in humor and tension release.-In comedy:...
, lack of interest/involvement, anhedonia
Anhedonia
In psychology and psychiatry, anhedonia is defined as the inability to experience pleasure from activities usually found enjoyable, e.g. hobbies, exercise, social interaction or sexual activity....
and inertia
Social inertia
Social inertia is a term that applies the concept of inertia to psychology and sociology. It is used to describe the resistance to change presented by societies or social groups, usually due to habit...
. The Anxiety scale assesses autonomic arousal, skeletal muscle
Skeletal muscle
Skeletal muscle is a form of striated muscle tissue existing under control of the somatic nervous system- i.e. it is voluntarily controlled. It is one of three major muscle types, the others being cardiac and smooth muscle...
effects, situational anxiety and subjective experience of anxious affect. The stress scale's subscales highlight levels of non-chronic arousal through difficulty relaxing, nervous arousal and being easily upset/agitated, irritable/over-reactive and impatient.
The main purpose of the DASS is to isolate and identify aspects of emotional disturbance; for example, to assess the degree of severity of the core symptoms of depression, anxiety or stress. The initial aims of the scale's constructions were to define the full range of core symptoms of depression and anxiety, meet rigorous standards of psychometric adequacy, and develop maximum discrimination between the depression anxiety scales. While the DASS can be administered and scored by individuals without psychology
Psychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...
qualifications, it is recommended that the interpretation and decisions based on results are made by an experienced clinician
Clinical psychology
Clinical psychology is an integration of science, theory and clinical knowledge for the purpose of understanding, preventing, and relieving psychologically-based distress or dysfunction and to promote subjective well-being and personal development...
in combination with other forms of assessment.
The Depression, Anxiety, and Stress Scales were developed by researchers at the University of New South Wales
University of New South Wales
The University of New South Wales , is a research-focused university based in Kensington, a suburb in Sydney, New South Wales, Australia...
(Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
) .
The test was developed using a sample of responses from the comparison of 504 sets of results from a trial by students, taken from a larger sample of 950 first year university student responses.
The test was then normed
Normalization (statistics)
In one usage in statistics, normalization is the process of isolating statistical error in repeated measured data. A normalization is sometimes based on a property...
on a sample of 1044 males and 1870 females aged between 17 and 69 years, across participants of varying backgrounds, including university students, nurses in training and blue and white collared employees of a major airline, bank, railway workshop and naval dockyard. The scores were subsequently checked for validity against outpatient groups including patients suffering from anxiety and depressive disorders, insomnia
Insomnia
Insomnia is most often defined by an individual's report of sleeping difficulties. While the term is sometimes used in sleep literature to describe a disorder demonstrated by polysomnographic evidence of disturbed sleep, insomnia is often defined as a positive response to either of two questions:...
cs, myocardial infarction
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
patients, as well as patients undergoing treatment for sexual
Sexual dysfunction
Sexual dysfunction or sexual malfunction refers to a difficulty experienced by an individual or a couple during any stage of a normal sexual activity, including desire, arousal or orgasm....
, menopausal and depressive disorders. While the test was not normed against samples younger than 17, due to the simplicity of language, there has been no compelling evidence against the use of the scales for comparison against children as young as 12.
The reliability scores of the scales in terms of Cronbach's alpha
Cronbach's alpha
Cronbach's \alpha is a coefficient of reliability. It is commonly used as a measure of the internal consistency or reliability of a psychometric test score for a sample of examinees. It was first named alpha by Lee Cronbach in 1951, as he had intended to continue with further coefficients...
scores rate the Depression scale at 0.91, the Anxiety scale at 0.84 and the Stress scale at 0.90 in the normative sample. The mean
Mean
In statistics, mean has two related meanings:* the arithmetic mean .* the expected value of a random variable, which is also called the population mean....
s and standard deviation
Standard deviation
Standard deviation is a widely used measure of variability or diversity used in statistics and probability theory. It shows how much variation or "dispersion" there is from the average...
s for each scale are 6.34 and 6.97 for depression, 4.7 and 4.91 for anxiety and 10.11 and 7.91 for stress, respectively. The mean scores in the normative sample did vary slightly between genders as well as varying by age, though the threshold scores for classifications do not change by these variations. The Depression and Stress scales meet the standard threshold requirement of 0.9 for research, however, the Anxiety scale still meets the 0.7 threshold for clinical applications, and is still close to the 0.9 required for research.