Delusions increase functional impairment in Alzheimer's disease.

BACKGROUND/AIMS Delusions in Alzheimer's disease (AD) may be associated with functional impairment. No studies to date have used functional instruments sensitive to changes in frontal executive function, possibly underestimating the impact. METHODS Patients with AD with and without delusions were administered cognitive tests and questionnaires to assess depression and quality of life. Caregivers were administered questionnaires to assess functional impairment, caregiver burden and behavioural symptoms. RESULTS AD patients with delusions (n = 19) when compared to AD patients without delusions (n = 19) matched for age, education and global cognitive function were significantly more functionally impaired based on performance on the Disability Assessment for Dementia Scale (p < 0.005). CONCLUSION AD patients with delusions have significantly worse functional performance.