0130 Reduced Entropy in EEG During Rapid Eye Movement Sleep in Men with Depression

Abstract Introduction Depression is an increasingly prevalent mental health condition. Patients with depression have disrupted rapid eye movement (REM) sleep as characterized by shortened REM latency, increased duration, and density. However, it unknown whether the dynamic patterns of EEG within episodes are altered in these patients. Here we investigated complexity during using analysis irregularity on multiple temporal time scales compared difference such a nonlinear property between patients controls. Methods We analyzed overnight recordings (256 Hz) collected from left central channel 19 older men age-matched otherwise healthy control Osteoporotic Fractures Men Study (MrOS) obtained National Sleep Research Resource (NSRR). To quantify irregularity/complexity fluctuations REM, Multiscale Entropy (MSE) was performed each 30-second epoch to calculate entropy at different ~0.004 ~0.078 seconds (i.e., 1/256, 2/256, …, 20/256 seconds). Results As men, had significantly lower values 0.023-0.031 (time scale =6/256 second: 0.363□0.008 [SE] for depression, 0.408□0.009 controls; =7/256 0.295□0.009 0.342□0.008 =8/256 0.225□0.009 0.269□0.008 all FDR-adjusted P-values< 0.001), indicating reduced fluctuations. The differences were not statistically significant smaller or larger scales. Conclusion complexity/irregularity depression. Our results indicate capability MSE capturing important features fluctuations, which might be missed those algorithms focused single scale. Support (if any) RF1AG059867, RF1AG064312. Heart, Lung, Blood Institute provided funding ancillary MrOS Study, "Outcomes Disorders Older Men," under following grant numbers: R01 HL071194, HL070848, HL070847, HL070842, HL070841, HL070837, HL070838, HL070839. NSRR supported (R24 HL114473, 75N92019R002).