Invited essay
A cognitive neuroscience account of posttraumatic stress disorder and its treatment

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Abstract

Recent research in the areas of animal conditioning, the neural systems underlying emotion and memory, and the effect of fear on these systems is reviewed. This evidence points to an important distinction between hippocampally-dependent and non-hippocampally-dependent forms of memory that are differentially affected by extreme stress. The cognitive science perspective is related to a recent model of posttraumatic stress disorder, dual representation theory, that also posits separate memory systems underlying vivid reexperiencing versus ordinary autobiographical memories of trauma. This view is compared with other accounts in the literature of traumatic memory processes in PTSD, and the contrasting implications for therapy are discussed.

Section snippets

Features of PTSD requiring explanation

What distinguishes the type of response to trauma that we label as PTSD? Among the most interesting features of PTSD are the disorganization and incompleteness of the trauma memory, the reexperiencing of the traumatic event in the form of spontaneous “flashbacks”, the time distortion typical of flashbacks, the unpredictable time course of intrusive memories connected with the trauma, and the sense of unreality that typically surrounds the traumatic event. We also know that many effective

Dual representation theory

In order to explain these phenomena a cognitive theory based on multiple memory systems was proposed by Brewin et al. (1996). According to their dual representation theory, memories of a personally experienced traumatic event can be of two distinct types, stored in different representational formats. One type of format (“verbally accessible memory” or VAM) supports ordinary autobiographical memories that can be retrieved either automatically or using deliberate, strategic processes. VAM

Cognitive neuroscience and fear

Much of our understanding of the brain mechanisms involved in the response to extreme fear comes from studies of conditioning. One important set of findings concerns the durability of fear conditioning. Consistent with observations about the frequent return of fear after successful psychotherapy (Rachman, 1989), it has been found that fear responses in animals can be easily reinstated following successful extinction, for example by placing the animal into a different context (Bouton &

Cognitive neuroscience and memory

For the purposes of this article the distinction between declarative and nondeclarative, or explicit and implicit, forms of memory is important to bear in mind even though it does not map exactly onto clinical observations of PTSD. Declarative memory involves representations of facts and events that are subject to conscious recollection, verbal reflection, and explicit expression (Eichenbaum, 1997, Squire, 1994). A prime example is autobiographical memory. Declarative memory is supported by a

The effects of fear on memory

From the foregoing review it may be inferred that the hippocampal processing of information about fear-evoking situations results in the laying down of integrated, coherent representations of conscious experience, located in the appropriate temporal and spatial context. These representations are available for deliberate recall. However, it is possible for information to reach the amygdala via a number of different routes, independently of the hippocampus. For example, the visual areas of the

The normal response to trauma

Having reviewed the relevant cognitive science findings, we are now in a position to amplify dual representation theory and put forward a more detailed model of the response to trauma. Consistent with proposals by several authors including Metcalfe and Jacobs (1998), Pitman et al. (2000) and van der Kolk (1996), a key component is the relative functioning of the amygdala and hippocampus. Owing to the stress-induced release of glucocorticoids and their effects on the hippocampus, verbally

What goes wrong in PTSD?

In the foregoing account a successful trauma response was related to the creation of detailed VAM representations that were fully integrated with pre-existing knowledge structures. Creating detailed VAMs can occur either during the trauma or afterwards, through deliberate focusing on flashback content and repeated conscious processing of detailed information about the trauma. The corollary is that failure to create these representations will result in a considerable amount of trauma information

Psychological treatment of PTSD

Standard treatment directed at PTSD symptoms generally involves two elements, which may be used separately or together: The detailed and repeated exposure to traumatic information, and the modification of maladaptive beliefs about events, behaviours or symptoms. Both exposure and cognitive methods have been demonstrated to be effective (Foa & Meadows, 1997). In accounting for the success of prolonged exposure, Foa and Rothbaum (1998) proposed that erroneous information in the trauma memory is

Conclusion

The study of trauma reveals many complex processes that are poorly understood. One of the most fascinating concerns the paradoxical nature of trauma memories, which may be vague or vivid, intrusive or quiescent, under or out of control, and experienced in the present or the past. There is now a large amount of converging evidence from clinical observation, neuroanatomy, and cognitive science to suggest that the many facets of trauma recall reflect the operation of two independent types of

Acknowledgments

I am very grateful for the comments of Bernice Andrews, Lucy Berliner, Anke Ehlers, Ann Hackmann, Allison Harvey, Mike Kopelman, John Morton and Mick Rugg on the ideas presented in this article.

References (91)

  • D.D. McCormick et al.

    Locus coeruleus lesions and resistance to extinction of a classically conditioned response: involvement of the neocortex and hippocampus

    Brain Research

    (1982)
  • H. Merckelbach et al.

    Traumatic intrusions as `worse case scenario's'

    Behaviour Research and Therapy

    (1998)
  • J. Metcalfe et al.

    Emotional memory: The effects of stress on `cool' and `hot' memory systems

  • L. Nadel et al.

    Memory consolidation, retrograde amnesia and the hippocampal complex

    Current Opinion in Neurobiology

    (1997)
  • S. Rachman

    The return of fear—review and prospect

    Clinical Psychology Review

    (1989)
  • 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 post-traumatic stress disorder

    Behaviour Research and Therapy

    (1999)
  • L.R. Squire et al.

    Retrograde amnesia and memory consolidation: A neurobiological perspective

    Current Opinion in Neurobiology

    (1995)
  • D.G. Amaral et al.

    Anatomical organization of the primate amygdaloid complex

  • Diagnostic and statistical manual

    (1987)
  • M.C. Anderson et al.

    On the status of inhibitory mechanisms in cognition: Memory retrieval as a model case

    Psychological Review

    (1995)
  • J.G. Armony et al.

    How the brain processes emotional information

    Annals of the New York Academy of Sciences

    (1997)
  • S.C. Benoit et al.

    Pavlovian conditioning and extinction of context cues and punctate CSs in rats with ibotenate lesions of the hippocampus

    Psychobiology

    (1999)
  • R.A. Bjork

    Retrieval inhibition as an adaptive mechanism in human memory

  • T.D. Borkovec et al.

    Worry: Thought suppression of emotional processing

  • M.E. Bouton

    Context, ambiguity, and classical conditioning

    Current Directions in Psychological Science

    (1994)
  • J.D. Bremner et al.

    Functional neuroanatomical correlates of the effects of stress on memory

    Journal of Traumatic Stress

    (1995)
  • C.R. Brewin

    Cognitive change processes in psychotherapy

    Psychological Review

    (1989)
  • C.R. Brewin et al.

    Fear, helplessness, and horror in posttraumatic stress disorder: Investigating DSM-IV Criterion A2 in victims of violent crime

    Journal of Traumatic Stress

    (2000)
  • C.R. Brewin et al.

    Acute stress disorder and posttraumatic stress disorder in victims of violent crime

    American Journal of Psychiatry

    (1999)
  • C.R. Brewin et al.

    Meta-analysis of risk factors for posttraumatic stress disorder in trauma-exposed adults

    Journal of Consulting and Clinical Psychology

    (2000)
  • C.R. Brewin et al.

    A dual representation theory of post traumatic stress disorder

    Psychological Review

    (1996)
  • C.R. Brewin et al.

    Effects of mode of writing on emotional narratives

    Journal of Traumatic Stress

    (1999)
  • A.R.A. Conway et al.

    Working memory and retrieval: A resource-dependent inhibition model

    Journal of Experimental Psychology: General

    (1994)
  • M.A. Conway et al.

    The construction of autobiographical memories in the self-memory system

    Psychological Review

    (2000)
  • M. Creamer et al.

    Reaction to trauma: A cognitive processing model

    Journal of Abnormal Psychology

    (1992)
  • G.C.L. Davey

    Trauma revaluation, conditioning and anxiety disorders

    Behaviour Change

    (1993)
  • R.J. Douglas

    Pavlovian conditioning and the brain

  • A. Ehlers et al.

    A cognitive model of posttraumatic stress disorder

    Behaviour Research and Therapy

    (1972)
  • A. Ehlers et al.

    Posttraumatic stress disorder following political imprisonment: The role of mental defeat, alienation, and perceived permanent change

    Journal of Abnormal Psychology

    (2000)
  • A. Ehlers et al.

    Psychological predictors of chronic post-traumatic stress disorder after motor vehicle accidents

    Journal of Abnormal Psychology

    (1998)
  • H. Eichenbaum

    Declarative memory: Insights from cognitive neurobiology

    Annual Review of Psychology

    (1997)
  • W.K. Estes

    Processes of memory loss, recovery, and distortion

    Psychological Review

    (1997)
  • M.W. Eysenck

    Depth, elaboration, and distinctiveness

  • E.B. Foa et al.

    Emotional processing of fear: Exposure to corrective information

    Psychological Bulletin

    (1986)
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