Delusions and behavioral disturbances in cognitively impaired elderly persons.

OBJECTIVE: To compare cognitive function and the prevalence of selected behavioral problems in delusional and non-delusional dementia patients. DESIGN: Retrospective medical record review. SETTING: An outpatient geriatric assessment center. PARTICIPANTS: 114 consecutive patients with dementia. MAIN OUTCOME MEASURES: Delusions as recorded in a consultation report. RESULTS: Delusions were described in 25.5% of patients. A variety of behavioral disturbances were more common in delusional than non-delusional patients, including agitation, angry or hostile outbursts, urinary incontinence, wandering or pacing, and insomnia. While cognitive function as measured by the MMSE was similar in delusional and non-delusional patients (18.9 +/- 3.8 and 19.2 +/- 5.9, respectively), there was a statistically borderline tendency for delusions to occur more often in patients in the mid-range of cognitive impairment (17 less than or equal to MMSE less than or equal to 23) compared with patients with greater or lesser degrees of cognitive impairment (32% vs 17% respectively). CONCLUSION: Delusions in dementia are associated with a variety of behavioral problems. Further studies are needed to clarify the role of delusions in the development of disruptive behaviors in dementing illness.