Sleep and intrusive memories immediately after a traumatic event in emergency department patients.

Kate Porcheret,Michael B Bonsall,Melanie Darwent,Guy M Goodwin,Sally A Beer,Emily A Holmes,Lalitha Iyadurai

doi:10.1093/sleep/zsaa033

Abstract

Study objectivesIntrusive memories of psychological trauma are a core clinical feature of posttraumatic stress disorder (PTSD), and in the early period post-trauma may be a potential target for early intervention. Disrupted sleep in the weeks post-trauma is associated with later PTSD. The impact of sleep and intrusive memories immediately post-trauma, and their relation to later PTSD, is unknown. This study assessed the relationship between sleep duration on the first night following a real-life traumatic event and intrusive memories in the subsequent week, and how these might relate to PTSD symptoms at 2 months.MethodsPatients (n = 87) recruited in the emergency department completed a sleep and intrusive memory diary from the day of their trauma and for the subsequent week, with optional actigraphy. PTSD, anxiety, and depression symptoms were assessed at 1 week and 2 months.ResultsA U-shaped relationship was observed between sleep duration on the first night and intrusive memories over the subsequent week: sleeping “too little” or “too much” was associated with more intrusive memories. Individuals who met Clinician-Administered PTSD Scale (CAPS) criteria for PTSD at 2 months had three times more intrusive memories in the first week immediately post-trauma than those who did not (M = 28.20 vs 9.96). Post hoc analysis showed that the absence of intrusive memories in the first week post-trauma was only observed in those who did not meet CAPS criteria for PTSD at 2 months.ConclusionsMonitoring intrusive memories and sleep in the first week post-trauma, using a simple diary, may help identify individuals more vulnerable to later psychopathology.

Highlights

We know little about symptoms immediately after a psychologically traumatic event and how these may relate to longer-term psychopathology
This study provides prospective, empirical assessment of sleep duration and intrusive memories immediately after a psychologically traumatic event and later posttraumatic stress disorder (PTSD) symptoms
A positive quadratic (U-shaped) relationship was found between sleep duration on the first night after the traumatic event and the number of intrusive memories of that event over the subsequent week: sleeping “too little” or “too much” was associated with having more intrusive memories

Summary

Introduction

We know little about symptoms immediately after a psychologically traumatic event and how these may relate to longer-term psychopathology. One symptom that may be a potential target for preventative interventions immediately after trauma is intrusive memories of the traumatic event. Intrusive memories of a traumatic event comprise a core clinical feature of both acute stress disorder (ASD, from 3 days to 1 month after a trauma) and posttraumatic stress disorder (PTSD, from 1 month after a trauma) [1]. As a single symptom (as opposed to a full diagnosis), can be significantly distressing and disrupt everyday functioning as early as the first week after a traumatic event, whether or not someone has a diagnosis of ASD or PTSD [2]. In the early period (on average 7 days) after trauma, intrusive memories have been centrally linked to other PTSD symptoms [3]. It has been suggested that targeting intrusive memories with early interventions may prevent PTSD from developing [5]

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