Measuring what?

A few days ago, the Mental Elf blog published an account of a new depression screening study. I have written about depression screening before (here is a link to the full version of my article on Beck Depression Inventory), so I wanted to see what’s changed. Well, it seems that not much. And this is what this post is about.

The test consists of two questions:

1. During the last month, have you often been bothered by feeling down, depressed or hopeless?

2. During the last month, have you often been bothered by having little interest or pleasure in doing things?

The author of the post, a psychiatrist, tells us that the two-question test has decent psychometric characteristics and, above all, it is so easy to use. After all, asking two questions will take just a moment, but the BDI with its 21 questions will take considerably longer.  Me? I can’t resist wondering whether the next step will be the ‘one-question’ test, followed shortly by the ‘special-look test’, which will take only 2 seconds, after which you will know whether I am depressed or not. I do beg your pardon – it’s whether: I need further assessment….

But, I know, I’m being mean now. The questions are not ‘that’ bad, are they? The use of ‘bothered’ attempts to make the questions more colloquial, they aim to focus on the person and yet…. So, here is a linguist’s take on the new two-question depression screening test.

1. My first point is that the questions are (just about) a replica of the two main diagnostic criteria of the depressive episode (ICD-10 F32-33). Here they are (quoting the ‘green book’):

(1) depressed mood to a degree that is definitely abnormal for the individual, present for most of the day and almost every day, largely uninfluenced by circumstances, and sustained for at least 2 weeks.

(2) loss of interest or pleasure in activities that are normally pleasurable.

That’s it, isn’t it? The screening test basically takes the two diagnostic criteria and puts ‘Have you been bothered’ in front and, hey, presto, here’s the screening test. And it works! What’s there not to like? But I wonder whether anyone has wondered about the circularity introduced by the questions. As you design the criteria and use them in questions, you are likely to reinforce them and make them even more ‘robust’. So you keep using them, after all they are robust, reinforcing them even more….Surely, it’s obvious, isn’t it?

If I understand the diagnostic manuals at all, and I might not, the diagnostic criteria are shorthand through which a clinician makes sense of very complex experiences people who come to see her or him with. In other words, as people tell the doctor how they suffer, s/he is trying to see whether what they hear can be shoehorned into the diagnostic criteria. And those, in turn, have never been designed to be used as questions for the patient whether in a screening test or an interview. This is because patients are supposed to talk ‘like patients’ and not ‘like medics’ (which Mishler taught us a long time ago). The screening test basically imposes a medical frame on the patient, which is neither theoretically sound nor practically useful.

Again: diagnostic criteria have never been designed to be used like questions and, second, they impose a frame which might not be shared by the patients, as Ziółkowska convincingly argues in her paper showing that patients do not understand doctors’ objectifying questions (link to Ziółkowska’s article).

Incidentally, the depressive episode lasts 2 weeks – no idea where the month comes from, second, hopelessness, while it features in the criteria of dysthymia, for example, it doesn’t appear in the criteria for depression. I’m sure the authors have their reasons, though.

2. Let’s now look at the form of the questions. Consider the first one:

During the last month, have you often been bothered by feeling down, depressed or hopeless?

I’m not going to comment on the oft-raised point that people do not have an in-built monitoring device. I, for example, would find it difficult to say that I have felt something for a month and not for three weeks. But that’s me.

So, let me start with that I’m puzzled by. It’s the list: “feeling down, depressed or hopeless.” What’s the difference by ‘feeling down’ and ‘depressed’? The question suggests that the two options are different, but for the life of me, I don’t understand the difference. Reference to hopelessness suggests that they can’t be the same thing with a different label. I also wonder if by ‘hopeless’ the authors mean hopeless I would understand or psychology would (do remember there are hopelessness scales).

But the question that bothers me some more is what happens, if I’ve been feeling down, but I haven’t been bothered by it. After all, it’s the umpteenth time, I’ve come to accept that this is the way I am and there is no cure, no help. I’ve accepted my fate. So, no, I haven’t been bothered by it, but yes, it’s hard, it’s very hard. I’ve no idea how many people would sympathise with such an account, but I have talked to people who said this to me. How would they answer your questions? I don’t know, but that’s hardly the point. The point is: do you know? Do you?

The second question is:

During the last month, have you often been bothered by having little interest or pleasure in doing things?

This is quite interesting, because the ICD-10 talks about ‘loss of interest or pleasure’, here we have ‘little interest’. And to be honest, I wouldn’t know how to answer such a question, as I think it is founded on a fallacy. In other words: what’s wrong with little interest? Why would you even ask such a question? Do people need much interest in order to be undepressed? I don’t know about the shrinks, but most people I know do not live lives full of constant excitement and pleasure. Just thinking about it makes me tired. And I’m not yet old.

What bothers me (is it the same bothering as in the question?) is that while the ICD10 criteria, unhelpful as they are, explicitly talk about change, the screening text simply pathologises ‘little interest’. That’s a very significant shift in the assessment and I keep wondering how aware the authors were of this. Of course, I do understand that the authors introduce the sort of ‘harmful dysfunction’ criterion (You do, don’t you?) through reference to being bothered, still, the problem is that you shouldn’t even ask me whether I am bothered by my ‘little interest’.

This is psychiatry that assumes that everybody has interests, hobbies, follows literature and politics (and knows who the British prime minister in the 1960s) and can easily count backwards in intervals of 7. Most people I know don’t have a hobby, some read, some don’t, and as for politics, well, it’s complicated. Can I be asked about Soviet politics, please?

There is also the issue of pleasure, but this post is getting large. I shall defer the pleasure of writing about pleasure till the next post.

 

So, let me end with the perennial argument – but it works. Gosh, it is as good as the BDI, which is not a scale and it imposes an assumption of depression in half the items, but, hey, isn’t it great? It also works!

Well, I’m not convinced. I am yet to read a convincing argument that such screening instruments offer more than evidence that they are underpinned by the same psy-discourse.  The cross-instrument correlation often given in evidence might (and I stress ‘might’) result not so much from instruments’ ability to gauge experience, but, rather, from their roots in the same dominant psychiatric discourse in which also the patient is submerged. The patient cooperates (more or less willingly) trying to give the ‘right’ answers.

The model of quantifying the experience of mental illness necessarily results in the dominance of medical discourse. The patient’s experience cannot surface as s/he plays the game, getting more ‘professional’ every time s/he is asked to complete a questionnaire or answer a screening test. The screening test works within the parameters of the dominant discourse, and so it successfully measures something which is invoked by this discourse.

So, what does it measure? To be honest, I have no idea, but I don’t rule out the possibility that it actually does measure something and that something might be depression. I suppose what I simply argue for is engagement with the above arguments. They are, in my opinion, non-trivial.

But no, I’m not holding my breath. You know, it’s ‘the linguist’, wink, wink, again.

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