Neuropsychiatric and behavioural correlates of sundowning in Alzheimer’s disease

Objectives: The aims of this study were to estimate the frequency of ‘sundown syndrome’ (SS) in a large sample of patients with Alzheimer’s disease (AD) and to assess its associated socio-demographic and clinical variables. Methods: Three hundred and sixty-one AD patients (age 78.4 ± 8.3 years) collected within the National Institute of Mental Health Genetics Initiative were included. A subsample was autopsy-confirmed. SS was identified within a caregiver-structured interview. Sociodemographic, clinical and neuropsychiatric features of sundowners and non-sundowners were compared by logistic regression. Results: One hundred eighty-five patients (51.2%) were sundowners. SS was positively associated with several neuropsychiatric symptoms (i.e., hallucinations, suspiciousness, wandering and aggression; all p-values < 0.01), and negatively associated with Mini-Mental State Examination and voluptuary habits (all p values < 0.05). Subsample analysis carried out in the autopsy group confirmed the findings. Conclusions: SS is common in AD and is associated with several neuropsychiatric features and voluptuary habits. The identification of SS predictive factors may allow preventive and targeted therapeutic interventions.