RCT Targeting Cognition in Early Alzheimer's Disease by Improving Sleep withTrazodone (Rest)

项目摘要-摘要

Project Summary - Abstract It is estimated that 5.8 million people are afflicted by dementia in the US, a number projected to increase to 14 million by 2050 unless effective therapies are available that prevent or significantly slow the disease process. Sleep complaints are common throughout the AD continuum beginning with prodromal stages. In observational studies, disturbed sleep has been linked to AD pathogenesis and subsequent development of mild cognitive impairment (MCI) and dementia. Co-investigator Dr. Bakker has studied pattern separation (PS; a memory task involved with the earliest stages of encoding that is essential to formation of new memories) in a task related functional MRI (fMRI) paradigm, determining that impaired PS is associated with increased hippocampal activation in amnestic MCI (aMCI). Because poor sleep may be associated with increased hippocampal activation, improving sleep is a potential target for positively affecting cognition and disease progression in AD. Trazodone is a generic antidepressant widely used off-label to treat sleep disturbance, particularly enhancing slow wave sleep (SWS) that is evidenced to be a critical sleep phase influencing pathogenic mechanisms. While it has been demonstrated to improve sleep in AD and potentially mitigate the risk of developing MCI, its effect on sleep has not been rigorously studied in MCI. Supported by its benign safety profile, we propose a rigorous double-blind, placebo- controlled, randomized crossover trial of trazodone in 100 subjects with prodromal AD/aMCI and sleep complaints. Each treatment phase will last four weeks with a two-week washout between phases. Sleep will be measured by home sleep testing including polysomnography, actigraphy, and self-report. Hippocampal function and excitability will be assessed by task-related fMRI employing PS. The primary outcome will be to examine the association of trazodone with sleep parameters. We hypothesize that trazodone will improve total sleep time and proportion of time in SWS. Secondary outcomes include assessment of trazodone's effect on 1) PS and hippocampal activation by task-related fMRI, with the hypothesis that trazodone will improve PS performance and decrease hippocampal activation; 2) a broader range of cognitive domains, with the hypothesis that trazodone will improve performance on other memory tasks, executive function, and processing speed; 3) neuropsychiatric symptoms with the hypothesis that they will improve with trazodone treatment. We will also assess blood-based biomarkers of amyloid and tau, as exploratory outcomes to assess their association with sleep and cognitive responses to trazodone.