Cognitive models assume that the incomplete integration of a traumatic experience into the
autobiographical memory results in typical symptoms associated with post‑traumatic stress disorder
(PTSD) such as intrusive re‑experiencing. Sleep supports the integration of new experiences into
existing memory networks through memory consolidation. In fifty‑six females, we investigated
whether a 90‑min daytime nap (n = 33) compared to a wake period (n = 23) after being exposed to an
experimental trauma (i.e. a trauma film) prevents PTSD analogue symptoms. Intrusive memories
were recorded for seven days using a diary, overall PTSD symptoms were assessed using the Impact of
Event Scale (IES‑R) and affective response to trauma cues were measured one week after experimental
trauma. The two groups did not differ in any of the analogue PTSD symptoms. However, participants
obtaining rapid eye movement (REM) sleep in the nap experienced less distressing intrusive memories.
Moreover, the duration of REM sleep and slow wave activity was negatively correlated with analogue
PTSD symptoms. Our findings suggest that even a short sleep period after experimental trauma can
play a protective role in trauma memory formation but only if the nap contains REM sleep. Our data
provide additional evidence for a critical role of REM sleep in PTSD development.
Scientific Reports | (2021) 11:4710 | https://doi.org/10.1038/s41598-021-83838-1