title: Normal ageing, impaired cognitive functioning and senile dementia--a mixture distribution analysis.
abstract: Dementia scores in the population of very old subjects (70 to > 95) do not demonstrate an obviously bimodal distribution. Heterogeneity analysis shows that the assumption of two distributions explains the data significantly better than a one-distribution model. The first distribution component can be regarded as representing the normal range of scores and the second the pathological range. An additional finding shows the normal range distribution shifting to the pathological range with increasing age.
authors.affiliation: Department of Psychiatry, Freie Universität Berlin, Germany.
authors.forename: F M
authors.initials: FM
authors.lastname: Reischies
authors.forename: R T
authors.initials: RT
authors.lastname: Schaub
authors.forename: P
authors.initials: P
authors.lastname: Schlattmann
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology; D003704:Dementia / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D011581:Psychological Tests