Delusions of Japanese patients with Alzheimer's disease.

Background: Delusions constitute one of the most prominent psychiatric complications in Alzheimer's disease (AD). However, there is little consensus of the prevalence and associated factors for delusions in AD.

Aims: To reveal the characteristics of delusions among Japanese patients with AD.

Method: 112 consecutive patients with AD were recruited over a one year period and administered the Neuropsychiatric Inventory (NPI).

Results: Delusions were present in 53 patients (47.3%). Delusions of theft were the most common type of delusion (75.5% of patients with delusions), followed by misidentification delusions and delusions of suspicion. More hallucination, agitation, and female gender were found in the delusions group.

Conclusions: The authors found a high frequency of delusions, particularly of delusions of theft and suggested that gender was associated with the expression of delusions in Japanese patients with AD.