Sleep Disturbances and Predictive Factors in Caregivers of Patients with Mild Cognitive Impairment and Dementia

BACKGROUND AND PURPOSE We examined the characteristics of sleep disturbances and sleep patterns in the caregivers of patients with amnestic mild cognitive impairment (aMCI) and dementia. METHODS We prospectively studied 132 patients (60 with aMCI and 72 with dementia) and their caregivers, and 52 noncaregiver controls. All caregivers and controls completed several sleep questionnaires, including the Pittsburgh Sleep Quality Index (PSQI). The patients were administered neuropsychological tests and the neuropsychiatric inventory to evaluate their behavioral and neuropsychiatric symptoms of dementia (BPSD). RESULTS The PSQI global score was 6.25±3.88 (mean±SD) for the dementia caregivers and 5.47±3.53 for the aMCI caregivers. The Insomnia Severity Index (ISI) and short form of the Geriatric Depression Scale (GDS-S) predicted higher PSQI global scores in aMCI caregivers, and higher scores for the ISI, Epworth Sleepiness Scale (ESS), and GDS-S in dementia caregivers. BPSD, including not only agitation, depression, and appetite change in dementia patients, but also depression, apathy, and disinhibition in aMCI patients, was related to impaired sleep quality of caregivers, but nighttime behavior was not. Age and gender were not risk factors for disturbed sleep quality. CONCLUSIONS Dementia and aMCI caregivers exhibit impaired quality of sleep versus non-caregivers. ISI, GDS-S, and ESS scores are strong indicators of poor sleep in dementia caregivers. In addition, some BPSD and parts of the neuropsychological tests may be predictive factors of sleep disturbance in dementia caregivers.