Clinical Review

Alzheimer’s disease

BMJ 2009; 338 doi: (Published 05 February 2009) Cite this as: BMJ 2009;338:b158

This article has a correction. Please see:

  1. Alistair Burns, professor of old age psychiatry1, honorary consultant psychiatrist2,
  2. Steve Iliffe, professor of primary care for older people3
  1. 1University of Manchester Psychiatry Research Group, Manchester M13 9PL
  2. 2Manchester Mental Health and Social Care Trust, Manchester
  3. 3Department of Primary Care & Population Health, University College London, London NW3 2PF
  1. Correspondence to: A Burns alistair.burns{at}

    Summary points

    • People with mild cognitive impairment are up to 15 times more likely to develop Alzheimer’s disease than those with normal cognition

    • Memory loss is a presenting symptom in most people who develop Alzheimer’s disease

    • The cause of Alzheimer’s disease is unknown, but genetic and environmental risk factors have been implicated

    • Cholinesterase inhibitors are safe and effective and can be prescribed for people in the moderate stages of Alzheimer’s disease

    • Antipsychotic drugs reduce agitation but are linked with an increased risk of mortality and impair cognition

    • Evidence is growing that some strategies are successful at preventing Alzheimer’s disease

    In this, the second of two review articles about dementia, we focus on Alzheimer’s disease, which is the most common cause of dementia. Dementia is a clinical syndrome characterised by a cluster of symptoms and signs manifested by difficulties in memory, disturbances in language, psychological and psychiatric changes, and impairments in activities of daily living. Alzheimer’s disease is a specific disease that affects about 6% of the population aged over 65 and increases in incidence with age.1

    Patients with Alzheimer’s disease are often identified and managed in primary care, where they may present diagnostic and management challenges. The benefits of early investigation and diagnosis of Alzheimer’s disease include instigation of pharmacological symptomatic treatments and initiation of psychosocial support, plus treatment of comorbid conditions. Here we review the diagnosis and medical management of Alzheimer’s disease, relying where possible on evidence from randomised controlled trials.

    What is Alzheimer’s disease?

    Alzheimer’s disease is a chronic progressive neurodegenerative disorder characterised by three primary groups of symptoms. The first group (cognitive dysfunction) includes memory loss, language difficulties, and executive dysfunction (that is, loss of higher level planning and intellectual coordination skills). The second group comprises psychiatric symptoms and behavioural disturbances—for example, depression, hallucinations, delusions, agitation—collectively termed non-cognitive symptoms.2 The third …

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