Construction of the Hospital Anxiety And Depression Scale (HADS)
The study was conducted in the setting of a general medical hospital outpatient clinic. The result of the study undertaken for this purpose was published under the title of The Hospital Anxiety And Depression Scale [11]. Full details of the method of construction of the HADS is given in the publication presenting it but, briefly, patients completed a questionnaire composed of statements relevant to either generalised anxiety or 'depression', the latter being largely (but not entirely) composed of reflections of the state of anhedonia. Thought was also given to whether the wording of the items would be easily translated to other languages. After examination by the physician, the researchers conducted an interview but were blind to knowledge of the patients' responses to the questionnaire. During that interview 'depression' was assessed according to the questions: " Do you take as much interest in things as you used to? Do you laugh as readily? Do you feel cheerful? Do you feel optimistic about the future?" i.e. there was not concentration on the anhedonic state alone. The 'anxiety' level was assessed by the questions: "Do you feel tense and wound up? Do you worry a lot? Do you have panic attacks? Do you feel something awful is about to happen?". The questionnaire responses were analysed in the light of the results of this estimation of the severity of both anxiety and of depression. This enabled a reduction of the number of items in the questionnaire to just seven reflecting anxiety and seven reflecting depression.(Of the seven depression items five reflected aspects of reduction in pleasure response). Each item had been answered by the patient on a four point (0–3) response category so the possible scores ranged from 0 to 21 for anxiety and 0 to 21 for depression. An analysis of scores on the two subscales of a further sample, in the same clinical setting, enabled provision of information that a score of 0 to 7 for either subscale could be regarded as being in the normal range, a score of 11 or higher indicating probable presence ('caseness') of the mood disorder and a score of 8 to 10 being just suggestive of the presence of the respective state. Further work indicated that the two subscales, anxiety and depression, were independent measures. Subsequent experience enabled a division of each mood state into four ranges: normal, mild, moderate and severe and it is in this form that the HADS is now issued by its publisher In the case of illiteracy, or poor vision, the wording of the items and possible responses may be read to the respondent.
Administration of the HADS
The HADS only takes 2 to 5 minutes to complete. It has been shown to be acceptable by the population for which it was designed [12]. However, as with any such questionnaire, caution must be observed; this is that the patient is, in fact, literate and able to read it. Some illiterate people are ashamed of their defect and will pretend to answer the statements by haphazard underlining of response options. It is reasonable practice for whoever administers the HADS to ask the intending respondent to read out aloud one or other of the phrases of the questionnaire. This also provides opportunity to provide explanation of the purpose of the questionnaire and assurance that, as with all clinical information, it is a confidential document which will aid their doctor to help them.
Since the instruction at the introduction to the HADS is to complete it in order to best indicate how the respondent has felt in "the past week" it is reasonable to administer the Scale again but at not less than weekly intervals. The record chart provided by the publisher enables a graphic display of progress rather in the manner of a chart for record of body temperature.
Further validation studies of the English and of foreign language translations of the HADS were undertaken in a variety of settings and centres. The first review of these [13] was published in 1997; the more recent [14] review of 747 identified studies concluded: " The HADS was found to perform well in assessing severity and caseness of anxiety disorders and depression in both somatic, and psychiatric cases and [not only in hospital practice for which it was first designed] in primary care patients and the general population".
In addition to frequent validation for use in the elderly the HADS has been validated for use in adolescents [15]
Obtaining the HADS
The HADS was placed with a publisher of test scales distribution of the Scale was placed with a publishing firm, the National Foundation for Educational Research (nferNelson: http://www.nfer-nelson.co.uk or email: information@nfer-nelson.co.uk). The firm supplies the scale, the chart for recording of scores and the manual with instructions for its use. Translations are available to all major European languages in addition to Arabic, Hebrew, Chinese, Japanese and Urdu; translation to other languages may be arranged by communication with the publishers. Other potentially useful scales obtainable from nferNelson include a measure of irritability alongside depression and anxiety, also a questionnaire to detect specific areas of anxiety e.g. hypodermic injections.
Examples of extracts from translation
Je me promets beaucoup de plaisir de certaines choses:
autant qu'auparavent [0], un peu moins qu'avant [1]
bien moins qu'avant [2], presque jamais [3]
sono riuscito a ridere e a vedere il lato divertente delle cose:
proprio come ho sempre fatto [0], non proprio come un tempo [1]
sicuramente non come un tempo [2], per niente [3]
ich kann lachen und die lustige Seite der Dinge sehen:
ja, so viel wie immer [0], nicht mehr ganz so viel [1]
inzwischen viel weniger [2], uberhaupt nicht [3]