P096 Objective Measures of Sleep Architecture in Adults and Older Adults with Depression: A Systematic Review and Meta-Analysis

Depression is intrinsically linked to sleep, however, the exact nature of sleep disturbances has been poorly defined, especially for older adults over 50 years with depression. We examined published articles with overnight EEG recordings in adults with and without depression to determine if objective measures of sleep macro and micro architecture differ. We also examined differences in these outcomes in older adults. 2135 papers were identified through four databases. Two reviewers, using the PICO structure, removed 2062 papers at abstract review and 58 at full text review. Fifteen articles met inclusion criteria and reported macroarchitecture. Three reported microarchitectural outcomes but were not meta-analysed. RevMan 5.4 software was used to perform a random effects model meta-analysis. NICE case-control guidelines were used for risk of bias. Fifteen studies were assessed (406 depressed and 432 control). Two papers examined older adults (31 depression and 31 controls). Within the total population, adults with depression had less total sleep time, lower sleep efficiency(SE), delayed sleep onset latency, higher wake after sleep onset, shorter rapid eye movement latency(ROL) and greater REM density than controls. No differences in stage 1(N1), stage 2(N2), stage 3(N3) or REM sleep were observed. In older adults, the depressed group had greater N1, less N2, shorter ROL, greater REM density and no difference in SE or in REM sleep duration. REM latency and REM density outcomes were consistent across older and younger depressed groups, whereas younger adults with depression had worse sleep continuity. Differences in sleep phenotype may relate to underlying neuropathology.