Hospital Anxiety and Depression Scale (HADS) was originally developed by Zigmond and Snaith (1983) and is commonly used by doctors to determine the levels of

anxiety Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...

and depression that a person is experiencing. The HADS is a fourteen item scale that generates: Seven of the items relate to anxiety and seven relate to depression. Zigmond and Snaith created this outcome measure specifically to avoid reliance on aspects of these conditions that are also common somatic symptoms of illness, for example

fatigue Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...

and

insomnia Insomnia, also known as sleeplessness, is a sleep disorder in which people have trouble sleeping. They may have difficulty falling asleep, or staying asleep as long as desired. Insomnia is typically followed by daytime sleepiness, low energy, ...

hypersomnia Hypersomnia is a neurological disorder of excessive time spent sleeping or excessive sleepiness. It can have many possible causes (such as seasonal affective disorder) and can cause distress and problems with functioning. In the fifth edition ...

. This, it was hoped, would create a tool for the detection of anxiety and depression in people with physical health problems.

Items on the questionnaire

The items on the questionnaire that relate to anxiety are *I feel tense or wound up *I get a sort of frightened feeling as if something awful is about to happen *Worrying thoughts go through my mind *I can sit at ease and feel relaxed *I get a sort of frightened feeling like 'butterflies' in the stomach *I feel restless as I have to be on the move *I get sudden feelings of panic The items that relate to depression are: *I still enjoy the things I used to enjoy *I can laugh and see the funny side of things *I feel cheerful *I feel as if I am slowed down *I have lost interest in my appearance *I look forward with enjoyment to things *I can enjoy a good book or radio or TV program

Scoring the questionnaire

Each item on the questionnaire is scored from 0-3 and this means that a person can score between 0 and 21 for either anxiety or depression.

Caseness of anxiety and depression

A number of researchers have explored HADS data to establish the cut-off points for caseness of anxiety or depression. Bjelland ''et al'' (2002) through a literature review of a large number of studies identified a cut-off point of 8/21 for anxiety or depression. For anxiety (HADS-A) this gave a specificity of 0.78 and a sensitivity of 0.9. For depression (HADS-D) this gave a specificity of 0.79 and a sensitivity of 0.83.

Factor structure

There are a large number of studies that have explored the underlying factor structure of the HADS. Many support the two-factor structure but there are others that suggest a three or four factor structure. Some argue that the tool is best used as a unidimensional measure of psychological distress.

Criticisms

The factor structure of the HADS has been questioned. Coyne and Sonderen argue in a letter published in the same issue, that Cosco, ''et al.'' provides grounds for abandoning HADS altogether. The HADS has also been criticised for its over reliance on

anhedonia Anhedonia is a diverse array of deficits in hedonic function, including reduced motivation or ability to experience pleasure. While earlier definitions emphasized the inability to experience pleasure, anhedonia is currently used by researchers t ...

as being the core symptom of depression, how single-item measures of depression may have the same predictive value as the HADS scale, as well as its use of British colloquial expressions which can be difficult to translate.

References