Sundowning in Patients with Dementia: Identification, Prevalence, and Clinical Correlates

The term sundowning is used to describe the emergence or worsening of neuropsychiatric symptoms in late afternoon or early evening in people with dementia.

Our aim was to evaluate sundowning's prevalence and clinical manifestations among patients attending a tertiary memory clinic and to investigate its clinical and neuropsychological correlates.

Patients with dementia attending our memory clinic were enrolled in the study. Sundowning was identified through a specifically designed questionnaire. Sociodemographic and clinical features of sundowners and non-sundowners were compared, and a logistic regression was performed to identify the variables associated with the phenomenon. A subgroup of patients underwent a complete neuropsychological assessment.

Among 184 recruited patients, 39 (21.2%) exhibited sundowning, mostly expressed as agitation (56.4%), irritability (53.8%), and anxiety (46.2%). Sundowners were significantly older, had a later dementia onset, exhibited more severe cognitive and functional impairment, more frequent nocturnal awakenings, and hearing loss relative to non-sundowners. They were also more likely to use anticholinergic medications and antipsychotics, and less likely to use memantine. In a multi-adjusted model, the factors significantly associated with sundowning were the Clinical Dementia Rating score (OR 3.88; 95% CI 1.39-10.90) and the use of memantine (OR 0.20; 95% CI 0.05-0.74). Participants with and without sundowning obtained similar results in single domain neuropsychological tests.

Sundowning is commonly experienced by patients with dementia and appears as a multiply determined condition. Its presence should always be evaluated in clinical practice and a multidimensional approach should be adopted to identify its predictors.