Rapid eye movement fragmentation, not slow-wave sleep, predicts neutral declarative memory consolidation in posttraumatic stress disorder.

This study sought to extend that literature by examining whether, in PTSD-diagnosed individuals, memory-retention deficits are present after a sleep-filled (but not after a wake-filled) delay (i.e., whether memory deficits can be traced to interruptions of sleep-dependent memory consolidation). Moreover, we investigated whether SWS- or REM-based disturbances, or both, contribute to retention deficits. We recruited participants into three groups: PTSD (n = 21), trauma-exposed non-PTSD (TE; n = 19) and healthy control (HC; n = 20). Using a crossover design, we assessed memory recall before and after an 8-hr period of polysomnography-monitored sleep and an 8-hr period of regular waking activity. PTSD-diagnosed participants retained less information than controls over the sleep-filled (but not wake-filled) delay. Furthermore, increased REM fragmentation predicted postsleep memory retention in PTSD-diagnosed individuals only. No SWS parameter was associated with or predictive of the amount of information retained postsleep. We conclude that specific REM-related changes in PTSD-diagnosed individuals affected sleep-dependent neutral declarative memory consolidation. Generally, these findings extend the literature suggesting that the co-occurrence of sleep and memory difficulties in PTSD is not accidental, but that these two symptom clusters are meaningfully related. Specifically, the study illustrates that subtle REM-related disruptions contribute most strongly to memory impai...
Source: Journal of Sleep Research - Category: Sleep Medicine Authors: Tags: J Sleep Res Source Type: research