Relationship Between Sleep the First Night and Week After Trauma and Subsequent Intrusive Memories: a Prospective Study From the Emergency Department

Most people will experience a psychologically traumatic event, such as a life-threatening accident, at some point in their life. In the initial days after such an event, it is common to be haunted by intrusive memories: image-based memories of the event that spring to mind unbidden. Intrusive memories can be distressing in their own right, but are also a hallmark symptom of post-traumatic stress disorder (PTSD).

Sleep is important for many functions involved in how people perceive, respond to and remember events, including stressful/traumatic events. Studies with patients who have experienced traumatic events indicate that sleep disturbances in the first weeks post-trauma are associated with later PTSD symptoms. However, in a previous study with healthy volunteers exposed to experimental trauma (film footage), those who were sleep-deprived in the first night, compared to those who slept, had fewer intrusive memories in the following week. This raises the question of how sleep in the first night, but also the first week, after real-life trauma is related to subsequent intrusive memories and PTSD symptoms.

The current study is an observational study of patients recruited from a hospital emergency department after a traumatic event. After completing brief baseline questionnaires in the emergency department, participants will be asked to fill in a daily diary of their sleep and intrusive memories over the following week. Post-traumatic stress symptoms, anxiety and depression will be assessed by post/online at one week and two months. Participants will be telephoned after two months to complete an interview to assess PTSD symptoms and an optional feedback interview.

This clinical study will be the first to assess the relationship between sleep in the first night and week, and intrusive memories and mental wellbeing after real-life trauma. Findings may have implications for developing simple sleep-based preventive treatments after trauma in the future.