Neuropsychological features of delusions in hospitalized older adults with neurocognitive disorders

Individuals with neurocognitive disorders (NCD) frequently experience psychotic symptoms, such as delusions. Delusions can contribute to other behavior problems, create dangers for patients and caregivers, and contribute to inpatient hospitalization of individuals with NCD. The current study aimed to identify cognitive symptoms associated with the presence of delusions and to differentiate delusion types based on cognitive profiles among hospitalized older adults with NCD. A review of electronic medical records of hospitalized older adults from an inpatient geriatric psychiatry setting yielded 185 patients with a diagnosis of mild or major NCD who had a neuropsychological evaluation during their admission and whose documentation described a clear delusion. We identified a comparison group of 185 patients without delusions well matched for age, education, and sex, and similar in global cognitive status. Exclusion criteria included delirium and history of a psychotic disorder. We first compared the groups' performances on a dementia battery. Then, cognitive performances of subgroups with specific delusion types (harm, theft, jealousy, and misidentification) were each compared to the remainder of the delusion-positive group. Exploratory analyses revealed that the delusion-positive group had a greater rate of discontinuation on Trails B and performed worse than the delusion-negative group on Trails A, Behavioral Dyscontrol Scale, Semantic Fluency, and Hopkins Verbal Learning Test-Revised (HVLT-R) initial registration. Theft delusions were associated with worse performance on HVLT-R recognition, misidentification delusions were associated with worse performance on Trails B, and harm delusions were associated with worse performance on a verbal generativity test. The presence of delusions in hospitalized older adults with NCD was associated with worse performance on several cognitive tasks with many being suggestive of associated with frontal-subcortical network integrity. Delusions of theft may be a consequence of reduced integrity of medial temporal lobe memory system.