Aggregated REM sleep measures calculated by standard sleep analysis in the summarized first 2 h of passive phase. Changes in the A) amount, B) episode number, C) episode duration and D) the latency time of REM sleep. Data are presented as mean ± SEM of 6-7 animals per group. *p < 0.05 means significant post hoc effects of RD-VEH group compared to the HC-VEH group; #p < 0.05 and ##p < 0.01 mean significant post hoc effects of and RD-SSRI group compared to HC-SSRI group. Groups: home cage-chronic vehicle treatment (HC-VEH); home cage-chronic escitalopram treatment (HC-SSRI); REM sleep deprivation-chronic vehicle treatment (RD-VEH); REM sleep deprivation-chronic escitalopram treatment (RD-SSRI).