Association between dementia and psychiatric disorders in long-term care residents: An observational clinical study

We examine the relationship between dementia and psychiatric disorder diagnoses among long-term care residents in nursing homes across the state of Rhode Island (RI), USA. Observational clinical study. Two hundred fifty-five residents with and without the diagnosis of dementia were included in this study. Prevalence analysis was used to elucidate information on psychiatric disorders in the overall cohort, and among residents with dementia. Questions from the quality of life questionnaire (EQ-5D-3L) that provides information on self-care, anxiety/depression, and resident's view of how healthy they are, were used to evaluate their association with dementia and psychiatric disorders. A logistic regression analysis was conducted to understand the relationship between dementia and mental illness diagnoses in long-term care facilities. Finally, a subgroup logistic regression analysis was performed for residents with Alzheimer disease. 65.1% of all residents suffered from at least 1 psychiatric disorder. Anxiety was the most common diagnosis (36.5%), followed by depression (28.6%), and insomnia (14.9%). There was a positive and statistically significant association between any mental illness diagnosis and dementia (adjusted OR: 3.73; 95% CI: 1.34–10.41). Bipolar disorder and insomnia were negatively and statistically significantly associated with dementia (adjusted OR: 0.17; 95% CI: 0.03–0.89 AND adjusted OR: 0.39; 95% CI: 0.16–0.96 respectively). Age and COPD were also statistically associated with dementia (adjusted OR: 1.07; 95% CI: 1.03–1.11 AND adjusted OR: 0.28, 95% CI: 0.12–0.66). Alzheimer disease was positively and significantly associated with the diagnosis of any mental illness (adjusted OR: 3.77; 95% CI: 1.17–12.20). We studied the relationship between dementia and diagnoses of psychiatric disorders present in long-term care residents. We found that residents with a diagnosis of dementia were more likely to suffer from at least 1 psychiatric disorder. Further work is needed to establish the neuropathophysiological relationship between psychiatric disorders and dementia.