1. What does the DASS measure, and what are its intended uses?
2. Who can administer and
interpret the DASS?
3. How do I get permission to use
the DASS?
4. How can I get the DASS manual?
5. What if I can’t afford the
manual – do I really need it?
6. Where can I get norms and
psychometric data (reliability/validity) for the DASS?
7. Where can I get clinical cutoffs and/or severity labels for the DASS?
8. What are the advantages and
disadvantages of the short (21-item) version of the DASS?
9. Can the DASS be administered
online or via a computer?
10. Can the DASS be used with children /
adolescents?
11. Are the three DASS scales independent from
each other?
12. What is the relationship between the DASS and
the tripartite model of Watson & Clark?
13. What is the relationship between the DASS and
DSM diagnoses?
14. What does the Stress scale measure?
15. Can I just administer one or two scales from
the DASS?
16. If I am interested in measuring stress,
should I only administer the DASS Stress scale?
17. Can I change the timeframe for the DASS?
18. Can the DASS be used to measure momentary
(“right now”) emotional state?
19. What reference do I cite for the DASS?
20. Can I put the DASS on my website?
21. Can I include the DASS in a piece of work I
am publishing?
22. Can I charge for administering the DASS?
23. Is the DASS resistant to respondents faking
good or bad?
24. Has the DASS been validated in XXXX
population?
25. Has the DASS been translated into language
XXXX? Can I translate the DASS into
language XXXX?
26. Is the total DASS score a useful measure?
27. What do I do with missing scores?
29. Who do I contact if I have a query about the
DASS?
Please see the Overview page.
The
DASS is a self-report instrument, and no special skills are required to
administer it.
However,
interpretation of the DASS should be carried out by individuals with
appropriate training in psychological science, including emotion, psychopathology
and assessment.
When
the DASS is administered to individuals who have sought professional help, or
who are displaying high levels of distress, interpretation should be carried
out by an appropriately qualified professional such as a clinical psychologist.
The
DASS questionnaire is public domain, and so permission is not needed to use it.
The DASS questionnaires and scoring key may be
downloaded from the DASS website and copied without restriction (go to Download page).
The DASS questionnaires and scoring key may also be distributed,
published or made available electronically, with the restrictions that:
a) the scales are not modified,
b) the scales are not sold for profit,
c) the intended audience is researchers
or health professionals rather than end users, and
d) reference is included to the DASS
website: www.psy.unsw.edu.au/dass/
The
DASS manual can be ordered for AUS$55 from the DASS website (go to Order page). Many University departments and clinical
services hold a copy of the DASS manual.
The
manual contains an extensive discussion of the theoretical background to the
DASS, as well as detailed information about DASS norms and interpretation.
However,
for many projects, the DASS can be used and interpreted without reference to
the detailed norms. Considerable
information about the DASS is available through published articles (see Publications page).
The
psychometric properties of the DASS and normative data for the DASS are
described in detail in the DASS manual (see FAQ4).
Additional
information is available through published articles (see FAQ5).
Tip: When interpreting alpha coefficients
(internal consistency), remember that alpha is strongly determined by the
number of items in a test. The more
items, the higher alpha will be. So it
is not appropriate to compare alphas between tests that have different numbers
of items.
Emotional
syndromes like depression and anxiety are intrinsically dimensional - they vary
along a continuum of severity. Hence the
selection of a single cutoff score to represent
“clinical” severity is necessarily arbitrary.
This is one of the fundamental differences between the DASS and
categorical measures based on psychiatric diagnosis (see FAQ13).
Recognising
the dimensional nature of emotional syndromes leads to a more sophisticated
assessment of disturbance. For example,
individuals who fall just short of a clinical cutoff
are correctly recognised as experiencing considerable symptoms and as being at
high risk of developing more extreme symptoms.
For most research purposes, it is much better to use DASS scores rather
than attempt to divide a sample into “normal” vs
“clinical” or “high” vs “low”.
However,
for clinical purposes, we recognise that it can be helpful to have conventional
labels to help characterise degree of severity relative to the population. Therefore we have developed a set of cut-off
scores for defining mild/moderate/severe/extremely severe scores for each DASS
scale. To avoid misinterpretation and
reification of these (arbitrary) labels, they are only provided in the DASS
manual – see FAQ4 and FAQ5.
Tip: The DASS severity labels are used to
characterise the full range of scores in the population, so "mild"
for example means that the person is above the population mean but still well
below the typical severity of people seeking help – ie
it does not mean a mild level of a “disorder”.
The
full DASS gives somewhat more reliable scores, and more information about
specific symptoms, but the DASS 21 has the advantage of taking only half the
time to administer. There are several
published studies showing that the DASS21 has the same factor structure and
gives similar results to the full DASS (see Publications
page). In general, the full DASS is
often preferable for clinical work, and the DASS21 is often best for research
purposes.
The
items in the DASS21 were selected on the basis of several criteria:
-
good factor loadings
-
coverage of all subscales within each scale
-
item means, such that DASS21 scores for each scale
should be very close to exactly half the full scale score
Remember
when using the DASS21 to multiply the obtained scale scores by 2, so that they
can be compared to the DASS normative data and to other published DASS
data.
Yes
the DASS can be administered by computer.
One advantage of using a computer, especially for research studies, is
that scoring can be automated.
We
do not endorse or distribute any particular programs. Whichever program you use, it is important
that computed scores are not made available to end users, and in particular
that you do not attempt to provide automated interpretation. This can be misleading and potentially
dangerous.
If
you wish to educate users regarding depression, anxiety and stress, we suggest
instead listing some key symptoms and pointing out that a) everyone experiences
these sorts of feelings/thoughts to some degree, but b) if they are
experiencing them frequently and strongly, they should consider seeking
professional help.
Finally,
please be aware that you are not allowed to charge money for distributing the
DASS scales, and this includes any computerised version.
The
DASS has been used with adolescents down to 14 years of age, but we have little
data from that age range to confirm the validity of the scales. We would not recommend using the DASS with
children below 14 years because it is likely that some children would not fully
understand all of the terms used.
Dr.
Marianna Szabo (marianna@psych.usyd.edu.au) at the
University of Sydney has been working on a simplified version of the DASS for
use with children/adolescents, and she may be able to provide further
information.
Alternatives
to the DASS for younger children include the Children’s Depression Inventory
(CDI) for depression, and the State Trait Anxiety
Inventory for Children (STAIC) or the Revised Children’s Manifest Anxiety Scale
(RCMAS) for anxiety.
No,
they are all moderately inter-correlated (typical rs
= .5 - .7). This characteristic is
shared with other scales that have attempted to provide “pure” measures of
anxiety and depression, e.g. the Beck Depression Inventory and the Beck Anxiety
Inventory.
We
regard the inter-correlations between the three scales not as indicating
conceptual overlap between the constructs of depression, anxiety and stress,
but rather shared causes. In particular,
genetic and other vulnerability factors tend to be general across all negative
emotional states rather than specific to one.
Similarly, environmental events and circumstances that induce negative
emotion tend to be partly general and partly specific.
The structure of the DASS has both
similarities and differences from the tripartite conceptual model proposed by
Clark and Watson. Both models emphasise symptoms of autonomic arousal in defining Anxiety
and differentiating it from other emotional syndromes such as Depression. Both models give emphasis to anhedonia in defining Depression, although the DASS gives
equal weight to other features such as hopelessness and devaluation of
life. However, the models differ with
respect to symptoms of tension and irritability. The DASS assumes that these symptoms define a
third, coherent syndrome that is distinct from both Anxiety and
Depression. The tripartite model, by
contrast, groups these symptoms together with other symptoms that both models
agree are nonspecific into a “General Distress” or “Negative Affect” category.
Factor analysis supports the contention that the
items in the Stress scale are not simply symptoms that are common to anxiety
and depression. If they were, then under
factor analysis the Stress items would have loaded modestly on both of the
Anxiety and Depression factors, rather than forming a separate factor as they
in fact do. Furthermore, the
longitudinal stability of the Stress scale supports its existence as a
distinct, coherent syndrome; see Lovibond (1998). Long-term stability of
depression, anxiety, and stress syndromes. Journal
of Abnormal Psychology, 107,
520-526.
Finally, the DASS assumes that the various
syndromes it attempts to measure are inter-correlated not because they share
common symptoms (indeed such nonspecific symptoms were excluded), but rather
because they share common causes, such as genetic and environmental
vulnerabilities, and environmental triggers – see also FAQ11.
In terms of traditional diagnostic
classifications such as DSM-IV, the DASS Anxiety scale corresponds most closely
to the symptom criteria for the various Anxiety Disorders, with the exception
of Generalized Anxiety Disorder (GAD). The DASS Depression scale corresponds
fairly closely to the Mood Disorders, although the diagnostic criteria for
those disorders include many symptoms that were rejected during DASS
development as not specific to depression (e.g., guilt, appetite change).
Finally, the DASS Stress scale corresponds quite closely to the DSM-IV symptom
criteria for GAD.
Psychometrically,
the DASS is quite different from diagnostic instruments in that it reflects the
underlying continuity of severity of symptoms in the population. DASS scale scores are dimensional rather than
categorical.
The Stress
scale, originally
labelled "tension/stress", measures a syndrome that is factorially distinct from depression and anxiety,
characterised by nervous tension, difficulty relaxing and irritability. It is quite similar to the DSM-IV diagnosis
of Generalized Anxiety Disorder (GAD).
Although
the stress scale can be distinguished from depression and anxiety in factor
analysis, it is important to note that all three syndromes are moderately intercorrelated (see FAQ11).
Omitting
a scale won't have any noticeable effect on scores for the remaining scales, so
if you're sure you won't need the data you can omit one or two of the primary
syndromes. However, depression, anxiety
and stress are so closely related that often it is useful to be able to
statistically control for one when assessing a relationship involving the
other. Journal editors will often insist
on such an analysis. If the intention is
to reduce administration time, it may be more cost-effective to simply use the
short version (DASS21) which has only 7 items per scale and is very quick to
administer.
As
noted in FAQ14, the DASS
Stress scale measures a relatively specific syndrome of tension/stress that is
narrower than the conventional conception of stress in terms of environmental
events triggering a wide variety of emotional symptoms.
Similarly,
the everyday use of the term “stress”, as for example in occupational stress,
is very broad and probably incorporates all three DASS syndromes.
Therefore,
in most cases all three DASS scales are relevant to the assessment of stress in
the broader sense.
There is no
problem in principle in changing the timeframe of the DASS questionnaire if you
are interested in a different time period, or if you wish to use a trait
wording (how do you feel “in general”).
However the data obtained will no longer be strictly comparable to the
DASS normative data or to other published DASS data.
The DASS is
not really suitable for this purpose, because several of the items refer to
situations other than the present (testing) situation, or experiences that are
relatively infrequent.
Alternative
instruments intended to measure momentary state include the Profile of Mood
States (POMS) and the Multiple Affect Adjective Checklist (MAACL).
The correct
citation for the DASS is the manual:
Lovibond,
S.H. & Lovibond, P.F. (1995).
Manual for the Depression Anxiety Stress Scales. (2nd. Ed.) Sydney: Psychology Foundation.
If
your website is only intended for health care professionals, then there is no
problem with including the DASS. The
easiest way is simply to provide a link to the DASS website: www.psy.unsw.edu.au/dass/
This
way users can download whatever information they need (long or short form of
the DASS, translations, references etc.) without you needing to put the files
on your website. Providing the web
address also ensures that any changes to the DASS website are made available to
visitors to your website, without you needing to check for updates.
Please
also see FAQ9 on
computerised administration.
In
general, yes, so long as the work is intended for researchers or health
professionals - see FAQ3.
Yes. While it is not permissible to sell the DASS
scales themselves to another person, it is quite acceptable to charge patients
for assessment that includes the DASS.
No,
like other self-report symptom-based scales, the DASS is transparent and it is
easy for a respondent to either disguise their symptoms (faking good or social
desirability) or exaggerate their symptoms (faking bad or malingering).
There
is no lie scale built into the DASS, but if there is reason to expect bias in
responding, it may be advisable to administer another instrument specifically
designed to assess such bias.
In
general, the best way to find out if the DASS has been used previously with a
specific population is to do a literature search, for example using PsycInfo.
It
is extremely unlikely that the factor structure will vary from one group to
another. Norms are irrelevant for most
special populations (e.g., people with dementia, alcohol abuse, chronic pain
etc. etc.) because there is no way of defining the particular group in a way
that will transcend culture, health service, severity etc. Therefore, the most substantive issue to
consider is whether the group in question is capable of understanding the items
and responding to them in an unbiased way.
In this respect, the DASS is no different from other symptom-based
measures.
In
general, unless you have particular reason to believe that the DASS will not be
valid (e.g., young age, low literacy, medication effects) then you can assume
that it will be valid.
See
also FAQ10 on lower age
limits for the DASS.
For
the latest list of translations, please see the Translations
page.
If
you are interested in translating the DASS into a new language that is not
already listed, please send an email to Peter Lovibond (p.lovibond@unsw.edu.au). The only restriction is that the translation,
like the original English DASS, must be public domain. This means that you would not be able to
copyright or sell the translation, and that you agree to make it available for
download from the DASS website.
Several
of the existing translations (e.g., Spanish, Chinese, Arabic)
contain references to papers describing the translation and validation process,
that might be useful to those planning new translations.
Yes
it is certainly both possible and sensible to add (or average) the three DASS
scores together to produce a composite measure of negative emotional symptoms.
If
you have access to the DASS manual (see FAQ4), the best way to do this
while retaining a connection to the normative data is to first convert each
scale score to a Z score (i.e., subtract mean and divide by SD from the
normative data for that scale) and then average the Z scores. Then you can compare the average Z score for
an individual or group to the severity labels in the same way as for individual
scales.
The
DASS is no different from other instruments with respect to missing
scores. If there is only one missing
item, there is no problem in averaging over the remaining items for the scale
in question. If there are too many
missing items, the validity of the DASS is compromised – in a research study,
the participant should be omitted, and in clinical work, the reasons for the
missing data should be explored.
How
many missing items is too many? There is no fixed standard
here. One rule of thumb is to allow up
to 2 missing items per 14-item scale for the full DASS, and 1 missing item per
7-item scale for the short version (DASS21).
Whatever choice you make about missing data, the most important
principle is to be explicit about the criteria in any report or publication.
Yes,
for most purposes you can simply score the first sheet as though it was the
DASS21 (remembering to multiply each scale score by 2 in the normal way for the
DASS21). This is possible because there
are 7 items from each scale on the first page of the full DASS.
If
you are conducting a research study and you are also a perfectionist, you can
adjust the scores to give the best possible estimate of DASS21 scores by
multiplying by the following correction factors (derived from the DASS
normative data set):
Depression:
1.04645
Anxiety: 1.02284
Stress:
0.98617
Please
check first to see if the answer to your query is included in this FAQ.
If
you have a query about ordering the DASS manual, please refer to the Order page.
If
you have a query about any other aspect of the DASS, please email Peter
Lovibond (p.lovibond@unsw.edu.au).