Mohammed T. Abou-Saleh

200 PRINCIPLES AND PRACTICE OF GERIATRIC PSYCHIATRYscientific significance of a result should rest on its replication byother workers on other samples; and on the development ofbiological evidence to support it as a risk factor in AD.Risk and Protective Factors for Alzheimer’s DiseaseA comprehensive review of the evidence for a wide range ofproposed risk factors, but also protective factors for AD, havebeen given by Jorm 8 and Henderson and Jorm 9 .Summarized, these are as follows:DefiniteAge.Family history.Specific genetic mutations (for familial cases only).Apolipoprotein E e4 allele on chromosome 19.Down’s syndrome.Awaiting confirmationRegional or ethnic differences.a-2 Macroglobulin gene.Head injury (interaction with apoE?).Previous depressive disorder.Herpes simplex virus.Cerebrovascular disease.UnlikelyAluminium in drinking water.Diet.Industrial solvents.Life stress.Electromagnetic fields.Possible protective factorsEducation, high premorbid intelligence or both.Anti-inflammatory drugs (NSAIDS).Oestrogen.Smoking.Moderate wine drinking.For vascular dementia, the review by Skoog 10 lists the same riskfactors as for stroke, namely hypertension, diabetes mellitus,advanced age, being male, smoking and cardiac disease. Anumber of recent case-control studies have suggested that vascularfactors may have a part to play in AD. There are as yet no casecontrolstudies of Lewy body or other less common dementias,although there is no impediment other than ensuring accuracy ofascertainment and recruitment of sufficient cases. The sameapplies to other under-researched areas of geriatric psychiatry,such as the psychoses of late onset, where case-control studiescould throw much-needed light on pathogenesis.It does seem justifiable to continue to search for environmentalexposures and other risk factors for AD, for vascular dementiaand possibly the rarer dementias. Case-control research may inthis way contribute not only to understanding their aetiology, butto finding preventive measures—the ultimate purpose of epidemiology.With the great expansion of the world’s elderly, thesocial significance of this would be inestimable.REFERENCES1. Schlesselman JL. Case-control Studies: Design, Conduct, Analysis.New York: Oxford University Press, 1982.2. Cole P. The evolving case-control study. J Chronic Dis 1979; 32: 15–27.3. Lilienfeld AM, Lilienfeld DE. Foundations of Epidemiology, 2nd edn.New York: Oxford University Press, 1980.4. Feinstein AR. Experimental requirements and scientific principles incase-control studies. J Chronic Dis 1985; 38: 127–33.5. Anthony JC. Case-control studies. In Henderson AS, Burrows GD(eds), Handbook of Social Psychiatry. Amsterdam: Elsevier, 1988;157–71.6. Henderson AS. An Introduction to Social Psychiatry. Oxford: OxfordUniversity Press, 1988.7. Armenian HK, Gordis L. Future perspectives on the case-controlmethod. Epidemiol Rev 1994; 16: 163–4.8. Jorm AF. Risk factors for Alzheimer’s disease. In O’Brien J, Ames D,Burns A (eds), Dementia, 2nd Edn. London: Kluwer Academic/Lippincott-Raven (in press).9. Henderson AS, Jorm AF. Disease definition, natural history andepidemiology. In Maj M, Sartorius N (eds), Evidence and Experiencein Psychiatry, vol 3, Dementia. Chichester: Wiley, 2000.10. Skoog I. Risk factors for vascular dementia: a review. Dementia 1994;5: 137–44.Results from EURODEM Collaboration on the Incidence of DementiaLJ Launer 1 , for the EURODEM Incidence Research Group*1Erasmus University Medical Centre, Rotterdam, The Netherlands, and National Institutes of Health, Bethesda, MD, USAIn 1988, European investigators formed the EURODEM networkto harmonize the protocols used in newly initiated populationbasedprospective studies on incident dementing diseases 1 .*Participants of the EURODEM Incidence Research Group: Department ofEpidemiology and Biostatistics, Erasmus Medical School, The Netherlands (A.Hofman MD, L.J. Launer PhD, A. Ott MD, T. Stijnen PhD); Epidemiology,Demography, Biometry Program, National Institute on Aging, US (L.J. LaunerPhD); Department of Psychiatry, Odense University, Denmark (K. Andersen MD,P. Kragh-Sorensen MD); Department of Psychiatry, Royal Liverpool UniversityHospital, UK (J.R.M. Copeland MD, M.E. Dewey PhD), INSERM Unit 330,France (J.F. Dartigues MD, L. Letenneur PhD); National Research CouncilTargeted Program on Ageing, Italy (L.A. Amaducci MD: now deceased); Institute ofPublic Health, Cambridge University, UK (C. Brayne MD); Department ofPsychiatry, Zaragoza University (A. Lobo MD) and Department of Neurology,University of Navarra, Spain (J.M. Martinez-Lage MD).Incident studies succeeded the case-control studies based onprevalent cases that were conducted in the 1980s 2 . Studies basedon incident cases are preferred to those based on prevalent cases,as the latter have several biases that affect the validity of theirresults 3 . Here we summarize the findings from the pooledEURODEM analyses on the frequency and risk for dementingdisease in the elderly.STUDY DESIGNThe pooled analyses are based on studies from Denmark 4 ,France 5 , The Netherlands 6 and the UK 7 . The sample includes