In previous studies, dementia was linked to a family history of dementia and Down's syndrome. This study tested the hypothesis that late-life depression accompanied by cognitive impairment in elderly individuals with no history of psychiatric illness is also associated with these family histories.

We investigated an age-stratified sample of 4051 elderly people in the community aged 65–84 (AMSTEL). The relationship between family history (CAMDEX questionnaire) and depression (GMS-AGECAT diagnosis) was studied.

A family history of mental health problems was associated with all subtypes of depression. Family history of dementia was associated with depression in subjects with a psychiatric history, but a family history of Down's syndrome was only associated with the combination of depression and cognitive impairment in subjects with no history of psychiatric illness.

The heritability pattern confirms the concept of a dementia-related subtype of late-life depression.

In previous studies cognitive impairment in depressed elderly in-patients tends to be associated with a late onset of depression. This study tests the hypothesis that cognitive impairment is associated with depression only in elderly individuals with no history of psychiatric illness.

We investigated an age-stratified sample of 4051 elderly people living in the community, aged between 65 and 84 (AMSTEL). The relationship between depression (GMS-AGECAT diagnosis) and scores on the Mini Mental State Examination was studied in subjects with and without a reported psychiatric history (CAMDEX questionnaire).

Low MMSE scores (MMSE ≤ 25) were only associated with depression in subjects with no psychiatric history (young/old: OR = 2.75, 95% CI = 1.83, 4.19; old/old: OR = 2.21, 95% CI = 1.61, 3.03).

We concluded that the combination of cognitive impairment and first-episode depression in elderly individuals may indicate cerebral deterioration. Depression as such may not be associated with cognitive impairment.