Background: This study compared the occurrence of psychiatric symptoms in a large group of community-residing participants enrolled in an Alzheimer's disease patient registry who met clinical diagnostic criteria for Alzheimer's disease or multi-infarct dementia, as well as mixed Alzheimer's disease and multi-infarct dementia.
Methods: Psychiatric morbidity observed from a psychiatric examination of 514 patients with Alzheimer's disease, 135 patients with multi-infarct dementia, and 86 cases with mixed dementia was analyzed using analysis of variance comparing symptoms across groups and chi-square test for differences in frequency of occurrence. Associations between pairs of symptoms were also reported.
Results: The frequency of occurrence and patterns of psychiatric problems were similar in patients with Alzheimer's disease and multi-infarct dementia. Agitation was the most frequent symptom, followed by depression, apathy, and behavioral disorders. Patients with mixed dementia had significantly more psychopathology.
Conclusion: This study demonstrated that significant psychopathology occurs in individuals with Alzheimer's disease or multi-infarct dementia. The high levels of symptoms in mixed dementia suggest that the two conditions have a synergistic effect on behavioral problems. The prevalence of multiple symptoms is higher than previously reported.