The nature of intrusive memories after trauma: the warning signal hypothesis

doi:10.1016/S0005-7967(01)00077-8

Behaviour Research and Therapy

Volume 40, Issue 9, September 2002, Pages 995-1002

https://doi.org/10.1016/S0005-7967(01)00077-8 Get rights and content

Abstract

Individuals who had experienced a range of different traumas were asked to describe the quality and content of their intrusive memories. Visual intrusions were the most common, and thoughts were uncommon. Intrusion quality varied little with type of trauma. Intrusive memories commonly consisted of stimuli that were present immediately before the traumatic event happened or shortly before the moments that had the largest emotional impact (i.e., when the meaning of the event became more traumatic). It is suggested that intrusive memories are about stimuli that through temporal association with the trauma acquired the status of warning signals, i.e., stimuli that if encountered again would indicate impending danger. This explains why intrusive memories are accompanied by a sense of serious current threat. The warning signal hypothesis may be useful in guiding therapists in identifying the moments with the largest emotional impact that will need reprocessing in treatment, and in educating patients about the nature of reexperiencing symptoms.

Section snippets

Childhood sexual abuse study

Thirty-five female survivors of childhood sexual abuse were recruited from a study of Wenninger and Ehlers (1998). Mean age was 36 years (SD=8.7). Eighty-six percent met DSM-IIIR symptom criteria for PTSD, as determined by the Posttraumatic Stress Symptom Scale (PSS-SR; Foa, Riggs, Dancu, & Rothbaum, 1993).

Ambulance service staff study

Fifty-six paramedics and technicians from the Oxfordshire Ambulance NHS Trust (77% men) were recruited from a study of Clohessy and Ehlers (1999). Mean age was 35 years (SD=8.7). Twenty-one

Method

Patients with PTSD who were assessed for treatment were asked to describe the content of their typical intrusive memories. They had experienced a range of traumas (e.g., accidents, combat, rape, physical assault, rescue operations).

Results

The interviews suggested that intrusive memories often consisted of stimuli that were present immediately before the traumatic event happened or shortly before the moments that had the largest emotional impact.

Examples:

•
A patient who had repeatedly been indecently

Discussion

Intrusive memories of trauma are often referred to as “intrusive thoughts”. The present data, in line with previous reports, show that this is misleading because these intrusions consist mainly of sensory impressions (Ehlers & Steil, 1995, Mellman & Davis, 1985, Van der Kolk & Fisler, 1995).

The predominance of visual recollections across all types of trauma is remarkable because one may have assumed that the most traumatic aspects of the event (and thus the most emotional) would be remembered

Acknowledgements

The work described in this paper was conducted at the Universities of Göttingen, Germany, and Oxford, UK. The research was funded by the Wellcome Trust.

References (18)

A Ehlers et al.
A cognitive model of posttraumatic stress disorder
Behaviour Research and Therapy
(2000)
M Reynolds et al.
Intrusive cognitions, coping strategies and emotional responses in depression, post-traumatic stress disorder and a non-clinical population
Behaviour Research and Therapy
(1998)
M Reynolds et al.
Intrusive memories in depression and posttraumatic stress disorder
Behaviour Research and Therapy
(1999)
R Steil et al.
Dysfunctional meaning of posttraumatic intrusions in chronic PTSD
Behaviour Research and Therapy
(2000)
R.A Bryant
Posttraumatic stress disorder, flashbacks, and pseudomemories in closed head injury
Journal of Traumatic Stress
(1996)
S.A Christianson
Emotional stress and eyewitness memory: a critical review
Psychological Bulletin
(1992)
S.A Christianson
Remembering emotional events: potential mechanisms
S Clohessy et al.
PTSD symptoms, response to intrusive memories, and coping in ambulance service workers
British Journal of Clinical Psychology
(1999)
A Ehlers et al.
Maintenance of intrusive memories in posttraumatic stress disorder: a cognitive approach
Behavioural and Cognitive Psychotherapy
(1995)

There are more references available in the full text version of this article.

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View full text

The nature of intrusive memories after trauma: the warning signal hypothesis

Abstract

Section snippets

Childhood sexual abuse study

Ambulance service staff study

Method

Results

Discussion

Acknowledgements

Behaviour Research and Therapy

Behaviour Research and Therapy

Behaviour Research and Therapy

Behaviour Research and Therapy

Posttraumatic stress disorder, flashbacks, and pseudomemories in closed head injury

Journal of Traumatic Stress

Emotional stress and eyewitness memory: a critical review

Psychological Bulletin

Remembering emotional events: potential mechanisms

PTSD symptoms, response to intrusive memories, and coping in ambulance service workers

British Journal of Clinical Psychology

Maintenance of intrusive memories in posttraumatic stress disorder: a cognitive approach

Behavioural and Cognitive Psychotherapy