“Generalized anxiety disorder (GAD) is one of the most common mental disorders; however, there is no brief clinical measure for assessing GAD. The objective of this study was to develop a brief self-report scale to identify probable cases of GAD and evaluate its reliability and validity.”

With these words, in 2006, the GAD-7 measure entered the world.

Before the-full scale rollout of the IAPT programme from about 2008/9 onwards, using the GAD-7 measure felt like a bit of a minority sport in the UK. The CORE measures (particularly the CORE-OM) were in far more common use, and pretty much the measure of choice within counselling in primary care services.

All that changed when the GAD-7, together with its sister measure for depression, the PHQ-9, were favoured as the default measures for reporting within the IAPT Minimum Dataset (MDS). Since then, though I don’t know the numbers, I think would be fair to say that GAD-7 and PHQ-9 are now the measures most commonly used in psychological therapy in the UK.

The GAD-7

7 item screening measure of symptoms of anxiety in previous two weeks

4-point Likert scale

Response options: Not at all; Several days; More than half the days and Nearly every day, scored 0, 1, 2, and 3, respectively

Scoring range 0 – 21

Clinical cut-off:  8 (UK: IAPT)

Reliable change index (RCI): 4 (UK: IAPT)

What is it?

The  Generalized  Anxiety  Disorder  (GAD-7)  questionnaire  is  a  seven-item,  self-report  anxiety  measure designed to identify probable cases of GAD and assess the severity of anxiety symptoms. It was developed over 2004 – 5 and tested in a network of 15 primary care sites located in 12 states in the US. [i]

The seven items were distilled from an initial pool of 13 items. Nine of these reflected the full range of symptom criteria for GAD from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV).  A further four items were included on the basis of a review of existing anxiety scales. After a period of rigorous testing of their relative properties, the 13 items were further refined down to the final seven.

What does it measure?

GAD-7 measures symptoms of anxiety and the extent to which the respondent has experienced them during the previous two weeks. The first three items relate to the two core criteria of the DSM-IV definition of GAD (see below). Response options are “Not at all,” “Several days,” “More than half the days,” and “Nearly every day.” These options are scored as 0, 1, 2, and 3, respectively.

Source BehaveNet 

Scoring the measure

The scoring range of each GAD-7 item is between 0 and 3, with 3 being the highest level of severity.

The client is guided to consider each statement and how often they have experienced feeling this way over the past fortnight. They are asked to then tick the box which corresponds most closely to their experience, using the categories at the top of each column from Not at all to Nearly every day.

A total score for the measure can be obtained by adding the totals for each column at the foot of each and adding these together in the Total Score T space shown above. This will give a figure of somewhere between 0 – 21.

What do the numbers mean?

Increasing scores represent higher levels of symptom severity. In terms of severity the following bands are commonly used:

0-5:       Mild anxiety

6-10:      Moderate anxiety

11-15:     Moderately severe anxiety

15-21:     Severe anxiety

According to the paper by Spitzer et al [i] a score of 10 or greater on the GAD-7 represents a reasonable cut point for identifying cases of GAD. Interestingly, however, in the UK, the IAPT programme guidance sets 8 and above as the cut-off for ‘clinical caseness’, and the reliable change index (RCI) at 4 points. This is the degree of change required for it to be classed as reliable i.e. change greater than might occur due to chance or measurement error.

Copyright, cost and where to obtain the measure

Copyright of the GAD-7 is held by Pfizer Inc. The measure is free to use and may be downloaded, along with the PHQ-9 and other instruments, at the PHQ website here

Instructions for both the Patient Health Questionnaire (PHQ) and GAD-7 measures can also be found on the PHQ website here

References

[i] Spitzer, R. L., Kroenke, K., Williams, J. B., & Löwe, B. (2006). A brief measure for assessing generalized anxiety disorder: the GAD-7. Archives of Internal Medicine, 166 (10), 1092-1097. Read the full article here   https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/410326

Further reading

Löwe, B., Decker, O., Muller, S., Brahler, E., Schellburg,D., Herzog, W. & Herzberg, PY. (2008). Validation and standardisation of the GAD-7  https://www.ncbi.nlm.nih.gov/pubmed/18388841

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Posted by:Barry McInnes

10 replies on “Made to measure: GAD-7

  1. Yet again a well explained article to help me to understand a well used therapy tool which sometimes I use so often that I don’t stop to think where it came from and how it was developed. Many thanks.

  2. I wonder what effect it has on clients to have their attention drawn each session to the level of anxiety/depressive symptoms they are experiencing? Does it make them focus more on the experience and therefore report it at higher levels than they might otherwise feel it? (Just thinking here of studies in social psychology of the salience effect – we tend to exaggerate the effect of things that draw our attention).

    1. Hi Caroline, what a great question. Maybe it depends on what the scores are saying. Am I improving or not? My rule of thumb is give a measure at the beginning of the session as a standalone then look at the trend if you have a number of measures. That way hopefully the client’s current ratings won’t be affected by previous ones.

      I guess also it underlines the importance of not making the measures ‘the thing’ but simply a reflection of our wider work together.

      Thanks for the thought provoking question! Barry

  3. The question is with GAD-7, is whether it is a useful measure?
    Having using it in IAPT, I find some overlap with the PHQ, and would prefer CORE if I had a choice. I also think the wording is more subjective than CORE.

    Would be interested to hear what others think?

    1. Hi Justine, you’ve posed another interesting question. Maybe another way of looking at it is ‘in what circumstances is GAD-7 useful?’ I could imagine using it if I were in an RCT focusing on anxiety alone, but that’s not going to happen anytime soon. Overall I prefer global measures like CORE rather than GAD and PHQ, as they seem to better reflect the reality of clients’ lives.
      Many thanks again! Barry

  4. Thank you Barry for the clear concise blog on outcome measurements
    I work in a small cancer charity and have raised the benefits of using Core 10 at our Counsellor Team Meetings. They all seem keen and I plan to bring along your information to help us get this up and running. There is great work being done in this charity wouldn’t it be good to get the evidence as well as to develop our practice?
    Marie Mc Guigan

  5. Thank you Barry for this fascinating article, I like this measure firstly because the questions seem highly relevant to clients lives. I feel the way the scores are done also make it easier for clients to score themselves. One critique with CORE is that some of the scores are a bit subjective, ‘Only Occasionally’ ‘Sometimes’ & ‘Often’ can mean very different things to different people. Somebody might go from feeling say anxious five days a week to feeling anxious three days a week but still honestly answer ‘sometimes’. Alternatively ‘Often’ to client A might mean daily, while client ‘B’ might feel ‘Often’ is three times a week. I believe by having a more precise scoring system, its more representative between clients and will be more likely to highlight improvement (which for many clients is a ‘virtuous circle’-seeing improvement encourages more improvement. Thanks for this interesting information kind regards Graeme

    1. Hi Graeme and thanks for the thoughtful reply.
      I agree that sometimes clients find the distinctions in CORE (especially the ones you mention) a little ambiguous. Though to be honest I’ve also found that with GAD and PHQ as it can be hard for clients to recall quite how often they’ve experienced something in the last two weeks, which is the recommended period. I’ve yet to find the ‘holy grail’ of the measure that is totally free of ambiguity. If you come across it please let me know!

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