Persisting Peritraumatic Dissociation Is Different From Evolution-Prepared Dissociation

Evolution-prepared dissociation provides a hyper-clear picture of the dangerous circumstances that evoked it. In contrast, non-evolution-prepared peritraumatic dissociation does precisely the opposite — it distances, obscures, pushes away, avoids, hides, and blocks a clear picture of the dangerous circumstances that evoked it. Researchers’ failure to distinguish between these opposite kinds of dissociation has prevented us from obtaining a clear empirical picture of (1) these two kinds of dissociation, and (2) their respective relationships to posttraumatic psychopathology (i.e., acute stress disorder [ASD], PTSD, and the dissociative disorders).

Evolution-Prepared Dissociation

As noted in’s last post (and in comments from several of you), evolution-prepared dissociation involves accelerated mental processing, a hyper-focus on the details of the dangerous situation, a subjective slowing of time, and a dissociative suppression of fear, pain, and other disruptive emotions. This ‘package’ of responses is a ‘gift’ that natural selection has given us. It is highly adaptive and it maximizes our ability to take effective action and, thereby, survive an imminently lethal situation.

Peritraumatic Dissociation

Note: “peritraumatic” literally means ‘near or around the time of the trauma.’  Contrast evolution-prepared evolution with DSM-IV’s description of peritraumatic dissociation:

“a subjective sense of numbing, detachment, or absence of emotional responsiveness; a reduction in awareness of his or her surroundings; derealization; depersonalization; or dissociative amnesia…” (American Psychiatric Association, 2000, p. 469)

This view of peritraumatic dissociation is inseparable from the idea that dissociation is a defense mechanism. For example:

“Dissociation leads to inner distancing and is thus to be regarded as a fundamental withdrawal mode enabling the person in question to phase out the unbearable reality for the moment and pretend that it has never happened.” (Breh & Seidler, 2007, p. 54)

Research on Peritraumatic Dissociation

Neither the researchers of peritraumatic dissociation, nor the instruments that they use to measure it, have drawn a clear distinction between defensive peritraumatic dissociation (which seeks to avoid reality) and adaptive evolution-prepared dissociation (which shines a bright spotlight on reality)! No wonder the research on dissociation that occurs near or around the time of the trauma (i.e., both kinds of dissociation) has produced modest and inconsistent results. Specifically, instruments that indiscriminately mix defensive peritraumatic dissociation with adaptive peritraumatic dissociation produce scores that are only modestly related to subsequent PTSD symptoms (Effect size = .34-.36). This effect size is significant, but not especially impressive.

On the other hand, researchers who have distinguished between immediate peritraumatic dissociation and peritraumatic dissociative symptoms that persist for weeks have found a very different result. Their multivariate statistical analyses show that immediate peritraumatic dissociation is unrelated to subsequent PTSD, whereas persisting peritraumatic dissociative symptoms are highly related to subsequent PTSD (Briere, Scott & Weathers, 2005). Similar results have been reported by other researchers (Halligan, Michael, Clark & Ehlers, 2003; Murray, Ehlers & Mayou, 2002; Panasetis & Bryant, 2003) .

It is important to note, however, that peritraumatic dissociation (whether immediate or persistent) is not the whole story when it comes to developing PTSD. That is, the same studies that revealed the importance of persisting peritraumatic dissociative symptoms also showed that

(1)many persons with no peritraumatic dissociation go on to develop PTSD, and

(2) many persons experience peritraumatic dissociation, but do not develop PTSD.

The Next Question About Dissociation

The next big question about dissociation at this point in our discussion is: “How and why does peritraumatic dissociation persist in some people? And perhaps become chronic? And why and how does peritraumatic dissociation persist a bit for some individuals, but then ultimately subside without any psychopathological after-effects?

What do you think?

This entry was posted in Acute Stress Disorder, defense, depersonalization, derealization, dissociation, dissociative disorders, evolution, evolution-prepared dissociation, measures of dissociation, peritraumatic dissociation, PTSD, published/presented research, trauma and tagged , , , , , , , , , , . Bookmark the permalink.

12 Responses to Persisting Peritraumatic Dissociation Is Different From Evolution-Prepared Dissociation

  1. Lynette Danylchuk says:

    I immediately think – what is the trauma and how severe is it; what is the context for the trauma, (experienced alone or with others, natural or man made); how old is the person who is traumatized and what, if any, support system is available after the trauma?
    There are so many factors that go into how a traumatic event impacts a person, and I think all of those factors need to be taken into account. We seem to be trying to evolve a unified theory of trauma, and I assume that will come from recognizing and integrating all the internal and external variables.
    Big job. We’re not alone in trying to do this. The people working in physics are very busy with this task, and they haven’t succeeded in doing this either – yet.

  2. I have just discovered this amazing discussion and I am impressed with the emphasis on expanding our understanding of dissociative experiences. I am an EMDR Level II trained clinician and I will be reading regularly…. I hope I can participate in the excellent thinking going on here!

  3. Dear Annabel,

    Welcome to! As an EMDR Level II-trained clinician, you know how important it is to be fully aware of your patients’ dissociative processes. I, too, hope that you will participate in our discussions about dissociation. Join the fun!
    PS. Was one (or both) of your parents a fan of Edgar Allan Poe?

  4. Thank you for having this blog for therapists. We have such a shortage of trained professionals to treat dissociation. When I had to leave the profession due to physical disability, only one therapist who accepted limited insurance was available. My clients with DID had nowhere else to go. The major hospitals in the area also do not acknowledge dissociation and treat as schizophrenia…overdrugged.

    Wish there were a way to reach all the appropriate resources, one city at a time, to improve the situation, including the colleges and grad schools still avoiding dissociation in the psychology and counseling curricula.

    A blog for the layperson wanting to understand dissociation:

  5. giolio says:

    How and why does peritraumatic dissociation persist in some people?
    Yes, this is a big question.
    I addressed it in my comment to another thread (on flashbacks – dissociative or not). Here is an arguable hypothesis — and I believe there is some evidence supporting it: If (1) evolved dissociation is linked to the strong activation of the 4f (fight-flight-freezing-faint) sytem, as it can be rather convincingly argued (see, e.g., Cantor, “The evolution of post-traumatic stress”, Routldge, 2004), and if
    (2) the activation of the 4f system is terminated by the activation of soothing interactions with an attachment figure when the traumatic event is over, then
    (3) peritraumatic dissociation may perhaps persist in people with an insecure Internal Working Model of attachment that hampers both seeking care and the fruition of provided care.

    • @giglio: I found your idea that this has something to do with attachment appealing. Persisting peritraumatic dissociation seems common, then it probably has a purpose. I doubt it is human only, but it might be hard to notice in other species.

      Well, I just arrived here. So my comment is perhaps not of much worth. However this site looks very interesting. I will be looking around. Thanks.

  6. Ivano Ancora says:


    I am an italian psychotherapist very interested in this blog, even if in my practice, usually I meet very few dissociative patients.

    I think “dissociation” is a too much broader label (adaptive? toxic? defensive? chronic? epissodic?).

    If whithin a label we could meet some contradictions, we need to review our label.
    One question could be: “What neuropeptides are responsible of these “altered states on consciousness”?

    There exists an endorpfine way to dissociation? (see U.F. Lanius’s works).

    What neuropeptides does work during evolution-prepared dissociation?

    What the individual differences could be in the light of the very early atthachment experiences?

    What differences if the “trauma source” is from “abroad” the family systems, what if it cames from the prymary care givers.

    Thank You for Your kind attention.

    Ivano Ancora

  7. ddnos1 says:

    Kudos Dr. Dell for this blog! It has been sorely needed and I am delighted to have found it! I have a dissociative disorder and find myself in exactly the reverse of yourself in that I have been puzzling over my own experiences and trying to match them to the available literature.

    I believe the single biggest factor in the development of PTSD is a persons integrative capacity. Integrative capacity being the sum of all factors. The more resources (internal + external) a person has the greater the capacity for integration. Whenever there is a deficit in the ratio of available resources /situational demands trauma can be said to have happened.

  8. brandic32 says:

    This is very interesting. Thanks for sharing.

  9. Aide Fusselman says:

    PTSD really takes some time to heal and a good family support is also needed. –

    My current blog site

  10. Annelle Polera says:

    The Vietnam War is one part of our dark history, an infamous conflict during the early 70s. This is a military event between the Communist forces of North Vietnam supported by China and the Soviet Union, and the non-communist forces of South Vietnam which was supported by the United States. It was a fierce battle between the Vietcong forces and the U.S Troops which ended after the Fall of Saigon in April 30, 1975.`

    Newly released write-up straight from our personal blog page

Leave a Reply to understandingdissociation Cancel reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s