Objectives:
The aim of this investigation was to study the relationship between delusions and depression in alzheimer's disease (ad).
Design:
This was a cross-sectional, case control study.
Setting:
Neuropsychiatry service, the johns hopkins school of medicine, usa.
Participants:
303 community-residing patients with probable ad according to nincds/adrda criteria were included in the study. seventy-five patients with delusions only were compared to a control group of 228 patients who had neither delusions nor hallucinations. patients with only hallucinations or both delusions and hallucinations were excluded.
Measures:
Patients were assessed clinically for the presence of delusions using the dsm-iv glossary definitions. they were also rated on standardized measures of depression, cognitive impairment, staging of dementia, general medical health, and functional impairment.
Results:
There was an association between delusions and depression among patients with ad. before adjustment for other variables, the presence of depression conferred a 1.8-fold (95% confidence intervals (ci) = 1.0-3.1; p = 0.04) higher risk of delusions. after adjustment for multiple other variables, this risk increased further to 6.8-fold (95% ci = 2.1-21.6; p = 0.001). conclusions; delusions in ad are strongly associated with depression after statistical adjustment for all confounding variables, which might distort this association. this finding has implications for our understanding of the etio-pathogenesis and management of delusions and depression in ad.