Evidence-based medicine and dementia

Claire Hilton describes how NHS policy in the current dementia crusade could distort good clinical practice.¹ I think the departure from evidence-based medicine is even greater than she suggests.

Case finding for dementia was introduced when there was no evidence (beyond anecdotes) that it was beneficial. We have known for a decade that screening for memory loss identifies less than one in five of those who will subsequently develop dementia syndrome.² We now have evidence that early psychosocial intervention has no effect on relocation to a care home, patient wellbeing, disease progression, dementia-related symptoms, or caregiver wellbeing.³

We have no evidence that memory clinics are the best way to reach diagnoses⁴ and grounds for thinking that their resources might be better used to manage dementia’s behavioural and psychological symptoms. We do not know that earlier recognition and intervention is harmless,⁴ and there seems little interest in finding out. We might be concerned that dementia now overshadows other problems of ageing, like depression and frailty.

We do know that the incidence and prevalence of dementia syndrome appear to be declining in many countries, including Britain,⁵ Germany, Spain, Sweden, the Netherlands, and the US.⁶ This may mean that prevention of cardiovascular disease is having an effect on brains. GPs’ performance in recognising dementia may be underestimated because of over-estimation of prevalence.

We have seen how poorly-evaluated, short-term projects to provide support or signposting have burgeoned and then disappeared; the familiar NHS disorder of ‘multiple projectitis’. And we also know that drug development has failed for a generation, with no symptom modifiers better than cholinesterase inhibitors, no disease modifiers at all, and no prospect of a ‘cure’ despite lots of ‘promising’ studies. We do not appear to understand the underlying pathological processes, have over-valued protein unfolding and deposition, and have undervalued the role of neuroprotection pathways.⁷

The Dementia crusade has been endorsed by politicians, particularly the Prime Minister. This has allegedly brought rising ‘awareness’ of dementia, and has yielded benefits for professionals and charities. Its effects on those with dementia are less clearly visible.

Competing interests

Member of the Alzheimer’s Society; member of the NICE/SCIE Dementia clinical guidelines development group 2004–2006; associate director of the national Dementias & Neurodegenerative Diseases Research Network (DENDRON) 2006–2015; working group chair for the National Dementia Strategy 2009.