As research casts doubt on screening tools, doctors debate pros and cons of their use in the chronically ill
Is it worth probing for depression?
By Lilian Anekwe
An elderly woman comes to the surgery for a review of a chronic condition – say diabetes or coronary heart disease – and you
notice a marked change in her outlook, attitude and general sense of wellbeing.
It is a situation GPs up and down the country face during consultations every day. But is this patient clinically depressed, or just weighed down by the mental burdens of living with a chronic illness?
How can GPs make this distinction? NICE recommends GPs use a simple two-question screening tool in the first instance, to identify patients who may be depressed and warrant investigation.
But as Pulse reported last week, a systematic review of the tools used in the QOF for screening patients with heart disease and diabetes found they were of little use – misdiagnosing as many as 62 per cent of patients.
Dr Tom Frewin says from his experience of using the tool in his surgery in Clifton, Bristol, that he 'can see what the researchers were getting at'.
'My worst problem is that a lot of my oldest patients, or those who can't get about or exercise like they are used to, are frustrated by not being able to do things. But is this depression, or just opening a can of worms?
'Some of these questionnaires are very good, but they're only good if they refer to the right people – young people with chronic diseases, or otherwise physically sick people. Not people who are 94. Who knows in what population they devised the tool?'
Dr Chris Manning, chief executive of Primary Care Mental Health and Education, supports the new focus on a patient's mental state, but has grown increasingly frustrated with what he calls the 'reductionism' of depression screening tools. 'Of course two to three simple questions will not be enough; they are the start, not the finish.
'The QOF has, at least, prompted clinicians to consider a patient's mental state – even
if this has been achieved at
the cost of sending many other doctors into spirals of despair at the sheer mindlessness and reductionism of it all,' he says.
Dr Joanna Trelawny, a consultant in cardiology at Leighton Hospital in Crewe, has seen a surge in the number of patients with a diagnosis of depression – and is worried about the toxicity of certain drugs in patients with heart disease.
She says: 'Virtually everyone over the age of 25 seems to be on an SSRI. I suspect at least 50 per cent of those on antidepressants don't need to be.'
But other specialists disagree, feeling the new focus on depression in patients with chronic disease comes not before time.
Dr Jurgen Pohl, a consultant in cardiology at the Leicester Nuffield Hospital, insists: 'The diagnosis is commonly missed. Even when depression is suspected it is rarely confirmed by formal testing or referral to psychiatric services.'
Seeds of suspicion
Where doctors seem to agree is that screening tools are more useful for planting the seeds of suspicion of a diagnosis, rather than for making it.
Dr Mark Ashworth, who has a research interest in depression as senior lecturer in the department of general practice at King's College London, thinks screening has had positive and negative outcomes. He says: 'The questions promote a healthy realignment in GP thinking, and reinforce our role as whole-person doctors.'
But Dr Ashworth, who is a GP in Kennington, south London, is concerned simple questionnaires can reduce screening to the asking of 'token questions'.
'It concerns me doctors may get into the habit of checking boxes, to be able to say "yes, I've been there, done that".'
Professor Tony Kendrick, professor of primary medical care at the University of Southampton, who is researching depression in primary care, finds questionnaires such as the PHQ-9, which are designed to assess severity, more useful than the two-question tool.
Professor Kendrick, a GP in Southampton, says: 'There's a big difference between tools designed for screening and severity measures. Two-question tests are never going to be accurate – they simply tell the doctor if a patient needs more tests.'
According to Professor Kendrick, 'the jury is still out' on whether screening people with CHD and diabetes for depression works.
'It's reasonable to ask about mood if patients suffer from CHD or diabetes, which have quite severe psychological effects. Even if the reasons for depression are understandable, this isn't a reason not to treat, or at least investigate.'
Dr Frewin agrees on balance screening is probably worthwhile. 'Whether it's worth the effort involved I don't know. But if you don't ask the questions, you can't make a diagnosis.'