The prevalence of depression in relation to cerebral atrophy and cognitive performance in 70- and 74-year-old women in Gothenburg. The Women's Health Study

Background. Hospital-based studies report that depression in the elderly is associated with brain atrophy. This notion could not be confirmed in a population study on 85-year-olds. We aimed to assess depression in relation to brain atrophy and cognition in 70- and 74-year-old women. Methods. A representative sample of 70- and 74-year-old women (N = 501) was examined with a psychiatric examination including the Mini-Mental State Examination (MMSE), measuring global cognitive function, and computerized tomography (CT) of the brain (N = 268). Depression was diagnosed according to DSM-III-R. Previous depression was diagnosed by history and by information from previous examinations in this 24-year longitudinal study. Results. The prevalence of depression was 11.6 %, including 8.4 % with major depression (MDD). Among those who were currently mentally healthy, 43.0% had a history of previous depression. Women with current MDD had lower scores on the MMSE than the mentally healthy women. This association was only found in women with a lower level of education. Current depressives, previous depressives and mentally healthy women without a history of depression did not differ on CT with regard to brain atrophy or white matter lesions. The association between MDD and lower cognitive performance was independent of the association of cognitive performance with structural brain changes on CT. Conclusions. Brain atrophy on CT is not associated with depression in the general population, despite the fact that individuals with depression have a worse cognitive performance. The finding that cognitive performance was not decreased in individuals with previous depression suggests that cognitive dysfunction is a state phenomenon in depression.