Overview

The term dissociation has been relatively obscure and ambiguous historically. The term “dissociation” itself lacks a single, coherent referent or conceptualization that all investigators in the field embrace (Cardena, 1994). Dissociation is best understood as a continuum or domain which captures a variety of phenomena. At it’s core, dissociation is a “lack of association” or a “break” between two or more mental processes. To dissociate is to “sever the association of one thing from another”, to separate certain information form conscious awareness. However, the term itself has been used to describe a myriad of phenomena ranging from hypnosis and information comprehension to cognitive responses to trauma. Such a wide range of applications makes the study of dissociation or dissociative amnesia quite difficult. Therefore it is important to state and recognize how dissociation has been defined over time.

How we conceptualize dissociation depends very much on how we view the process of mental functioning and the phenomena of dissociation itself. The first important point is that the mental process can be viewed in two different and diametrically opposed ways. One view of dissociation starts with the assumption that mental processes normally represent some kind of unity (Woodly, 1994). Following this assumption, then, dissociation would be the breakdown of this unity or the severing of the “links” between normal mental processes. The other view of dissociation assumes not unity but multiplicity which constitutes normal functioning. That is, that there exists a hierchy of controls in the mind which are interconnected and coexist. Dissociation, in this view, would occur when one such higher level of control became dysfunctional and allowed “less-able” levels to become dominant. A further difference in viewing the phenomena of dissociation is by conceptualization not of psychological constructs, but of biological functions. From this view, dissociation occurs via a neurological or biochemical malfunction, thus disrupting the normal flow of mental processes. Each of these views is inherently different and each carries with it consequences for the assessment and treatment of dissociative disorders.

Dissociation in the Unified Mind

Dissociation in the unified mind occurs when there is a break or a barrier in normal functioning. In this view, the mind processes all conscious experiences as a single unit. This can be seen and has been described as the “amnesic barrier” wherein a system of ideas become disconnected from consciousness (Woody, 1994). The best example of this can be seen in E. R. Hillard’s “hidden observer” phenomenon which occurs through hypnosis. Here, part of the person (the hidden observer) knows about pain that the other, conscious part of him or her, knows nothing about (Woody, 1994). In this and other such instances, hypnosis can be described as “spontaneous amnesia”. This is not to say that while there has been information consciously processed by the individual, that information is not directly available and thus assumed lost. However, according to this view, this information is simply stored in a parallel stream of consciousness which has become either “detached” or “blocked”.

Here another important distinction is recognized, that is, amnesia as a temporary barrier to the recall of information. While this information may appear to be lost, according to this view, this may only be a temporary phenomenon. The information may once again be made readily available when the streams of consciousness are tapped or brought together. A suitable analogy is that of the conscious mind as televised event in which a great variety of events are occurring simultaneoudy, 1994). Therefore, once attention is directed to the desired information, it may again be made available.

Dissociation Via Multiple Processes

According to this view, the mind is already, in a sense, deeply divided (among many parallel modules), and higher consciousness functioning somehow acts to bridge these gaps (Woody, 1994). There are many such views among this type that have gained widespread acceptance among the psychological community. One such view is known as Neodissociation theory and has at it’s core, three basic assumptions. The first assumption is that subordinate cognitive systems exist, each of which has some degree of unity, persistence, and autonomy of function (Hillgard, 1994). Under normal functioning these subordinate systems are seen to interact effectively, but at times, like during dissociative episodes, they can become disjointed. It is held that it is during this time that one or more of the normally cooperative systems of the mind overtakes more control than usual. However, since this these subordinate systems are not capable of long term control this state is not permenant and at some time control is yeilded back to the collective and the system is reintegrated. The belief also holds that during this time of dissociation the system which possessed control also possesses the “imprint” of experiences from that time. Therefore, upon reintegration it is possible that these experiences are not incorporated back fully into the overall consciousness. It is in this manner that dissociative amnesia is believed to occur.

The second assumption is that some sort of hierarchal control exists that manages the interaction or competition between and among these structures. A third assumption is that there must be some sort of overarching monitoring and controlling structure (Hilgard, 1994). It is this state of control that operates to ensure normal functioning. Dissociation can occur when this system either dysfunctions or is made dormantelief in this hierarchal structure rests in the notion that without some such mechanism the systems of the mind would be expected to take control almost at random, both within the individual and between individuals. Hilgard expresses this belief saying that in the absence of such a controlling structure, we would be forced to conclude that hierarchy is determined by the relative strength of each of the structures (as in the pecking order of barnyard fowl).

Dissociation and the Psychobiological Model

While the preceding discussion has centered around theories of the mind in abstract conceptualizations such as streams of consciousness, this approach emphasizes the observable, physical and chemical functions of the brain and body. According to this view dissociation may be best explained by the neurochemical and electrical activity which occurs within the brain. By this model, dissociation may occur when neurochemical levels change outside a “normal” range or when electrical activity within the brain becomes “abnormal”. Medical research in this area has revealed many of the mechanisms which may act in this capacity. It has been shown that the catecholamines norepinephrine, epinephrine, and dopamine are chemical messengers that are released in response to stress as part of the “fright, fight, or flight” response both within the brain itself and via the peripheral nervous system throughout the rest of the body (Brown, 1994). Studies have shown that during periods of stress, levels of catecholamines in plasma and urine are increased. In those diagnosed with Posttraumatic Stress Disorder it was found that these levels remained higher, even at rest, than did levels in control groups. These studies have also shown that such individuals have lower feedback from Alpha-2 receptors which are believed to regulate the production of norepinephrine. These individuals have shown to have increased arousal to specific stressors, more anxiety, and a high number of dissociative episodes, including dissociative amnesia.

It follows from this view, then, that dissociation may occur when these levels of catecholamines cannot be regulated. Individuals may be predisposed to dissociative disorders due to improper functioning of the Alpha-2 receptors. When exposed to increased levels of anxiety, it becomes increasingly likely for such individuals to experience a dissociative episode, such as dissociative amnesia. Therefore, treatment from this perspective, would most likely involve the use of medications designed to reduce the levels of such neurochemicals.

Another, though less documented view of dissociation within psychobiology is that of cerebral function. The belief from this standpoint is that fluctuations in electrical activity in the brain may be the cause of, or a significant factor in, dysfunction. Currently, medical technology aids in research to record the spontaneous fluctuation of voltage in the entire brain as they are recorded from the surface leads (known as an Electroencephalogram) (Brown, 1994). Though little conclusive research has been done using EEG’s, it is believed that increased or decreased electrical activity in key areas of the brain may be a significant factor in dissociative episodes. Similar research, in the area of bloodflow, has yielded somewhat better, though still not conclusive results. It has been found that decreased blood flow to certain areas of the brain can trigger a “shift’ in personalities in individuals diagnosed with Multiple Personality Disorder (now Dissociative Identity). Similarly, it is believed that this same phenomenon may help to explain certain types of dissociative amnesia.

As we can see, there are many ways of looking at the mind and it’s functions. The mind can be seen as a mostly physical entity, functioning via chemicals and electrical impulses traveling along pathways. In this a case we may expect to see dissociation occur when one or more of these mechanisms dysfunctions. It follows, then, that treating dissociative disorder would involve strictly physical and chemical interventions relying on the advances made in medicine and science. We may, however, we may see the mind in more abstract and psychological terms. We may see this type of -mediating whole or as a collection of interconnected parts which, in cooperation, function as a whole. While either of these later views would assume more indirect treatment patterns, the specific methods of treatment may differ dramatically. Therefore, it is of utmost importance that we “keep in mind” these differing views, for they have a tremendous impact on our assessment and treatment of dissociation and dissociative amnesia specifically.

Research in Dissociation

In order to understand dissociation best, we need not only to view the most popular theories, but also how dissociation is seen “in the real world”. No amount of theorizing or conceptualization can itself teach us about dissociative amnesia. While theories are exceptionally useful tools, they do not paint the whole picture. It is here that I hope to cover the other side of dissociative amnesia which, when coupled with theory, helps to further our total understanding.

Dissociative amnesia as defined in the DSM-IV, involves three major features: The predominant disturbance is one or more episodes of inability to recall important personal information, usually of a traumatic or stressful nature, that is too extensive to be explained by ordinary forgetfulness. Secondly, the disturbance does not occur exclusively during the course of Dissociative Identity Disorder, Dissociative Fugue, Posttraumatic Stress Disorder, Acute Stress Disorder, or Somatization Disorder, and is not due directly to a substance or general medical condition. Lastly, the disturbance must cause clinically significant distress or impairment in social, occupational, or other important areas of functioning. Therefore, with a definition of Dissociative Amnesia in hand and views of the phenomenon in mind we may now take a brief look at what some research in the area has uncovered.

Dissociation as a Response to Stress

Researchers and clinicians alike believe that Dissociative Amnesia may be a specific response to stress. Freud, many years ago, referred to repression as a defense against traumatic, unwanted, or unacceptable information. Many since then have expressed differing views along similar lines. As we have discussed much research supports to\he notion of dissociative amnesia occurring in response to some traumatic event. Surely the most widely studied area supporting this view involves children who have experienced some abuse, most commonly, sexual abuse. According to Ross (1992), “severe childhood trauma causes a long lasting dysregulation at all levels of the organism...” (Shirar, 1996). In animal studies, traumatic stress has been shown to cause long term changes in brain regions involved in memory (Bremner et al, 1996). This research supports a psychobiological theory in that dissociative amnesia is due, at least in part,. To psysiological changes in the brain. Animal research, done by van der Kolle and Greenberg showed that animals that underwent inescapable trauma (electric shocks) had measure Hthese changes, which included increases in norepinephrine and epinephrine among other chemicals, lead to behavioral helplessness. While the psychological state of the animals is immeasurable, similar processes have been translated to humans. For children, dissociative amnesia is viewed as a defense “against the inescapable trauma which has been experienced”. Since it is believed that children have few ready defenses at this point, dissociation is functional “with it’s ability to help the child forget or deny the event, or disown the feelings and the pain, both during and after the abuse” (Shirar, 1996). The overall theme expressed by this research is this: Trauma, especially in childhood, may alter the brain significantly, both dissociating the traumatic events and leading to a predisposition for future dissociative episodes.

Other research in this area has yielded different, almost opposite results. Much research has concluded that children who have experienced trauma are able to recall events of the trauma quite well. Studies done which attempt to expose children to events similar to those of childhood trauma have shown no difference in memory during stressful and non-stressful events. Some such experiments found that there was no difference in memory between children who underwent blood drawing (stressful event) and children who interacted with a friendly stranger. Some similar studies, aimed at testing the reliability of children as witnesses, have shown that children are also quite resistant to suggestion. These studies have shown that children are quite resistant even when reporting abuse; studies show that it is very rare for children to make errors of commission, even with suggestive questions such as, “he took your clothes off, didn’t he?” (Bremner et al, 1996). Still others studies show that stressful events actually enhance the recall ability for central details. With such conflicting findings it is difficult if not impossible to make generalizations. However, a concession may be found in the statement that dissociative amnesia may occur in some individuals, given certain circumstances. Whether this statement is true and who and what these circumstances are is not, at present, known.

Dissociation and Hypnosis

A wide held belief is that dissociative amnesia can be understood as analogous to hypnosis. As stated earlier it is held that amnesia may occur when certain facets of the mind become dissociated or when lower levels of consciousness are allowed primary control. Again, there are two differing theories as to how and why this may occur; Whether a unified mind become disconnected via the “amnesic barrier” or whether a deeply divided mind shifts the mechanism of primary control to as lower, “less able” system. Whichever be the case, the research in this field is aimed simply at supporting the broader conceptualization of amnesia as explainable via a hypnotic-like state.

In studies reviewed by Bennett (1988), surgical patients were issued suggestive communications while under general anesthesia. It was found that patients who had received the suggested communication then elicited the suggested behavior six times more often than those who did not. What is more, none of the patients in the experimental condition were later able to recall the suggestive communication, even when hypnosis was employed to aid them in recall (Klein, 1994). Further studies reviewed by Evans (1979) not surgical patients but subjects issued suggestive communications, paired with a cue, during sleep. It was found that the cue elicited an appropriate discriminative response a reasonably high proportion of the time as much as five months later. All of this transpired without any evident waking memory for the original, sleep administered suggestion (Klein, 1994).

In all, what does this research tell us? It tells us a lot and at the same time not much at all. What it does say is that if we are correct, dissociative amnesia does seem to share many characteristics with hypnosis. The results found studying hypnosis may be integrated into the larger framework in this manner: A hypnotic-like state, in the mind, may be triggered by certain stimuli, be they stressful or not. The individual, still capable of acting within reality may be completely unable to recall the events that transpired during this state. However, how and why these stimulus lead to a hypnotic episode is a link which is much harder to make and to understand. In order for such results to gain prominence, much more research will be needed to gain a clearer understanding of this process at work.

Assessment and Treatment of Dissociative Amnesia

Having now looked at the basic theories of dissociation and the empirical findings, we turn now to the assessment of dissociative disorders and dissociative amnesia. While to this point we have stresses the underpinnings and processes of dissociation here we will look at the clinical realities of dealing with dissociative amnesia. Once again, however, it is important to keep in mind the fact that how we believe this phenomena occurs, influences how we assess and treat it.

Assessment of Dissociative Amnesia

The assessment of dissociative amnesia in the clinical setting is very much problematic. While most estimates of rates of the disorder are fairly low, they are still much higher than most clinicians are trained to expect. It is not surprising, then, that those with dissociative disorders are frequently misdiagnosed and spend years in the mental health system before receiving an accurate diagnosis (Carlson, 1994). However, many tools for measuring dissociative experiences have significantly aided in diagnosis. One such measure, the Dissociative Experiences Scale (DES), is a 28-item self report instrument. A typical DES question is, “some people have the experience of finding new things among their belongings that they do not remember buying. Mark the line to show what percentage of time this happens to you.” (Ross, 1991). The subject may then circle a point on a line which ranges from 0% to 100%.

While this instrument has proven to be quite useful in screening, it is far from diagnostic. In a study of the DES it was found that only 17% of those scoring 30 or above actually had a diagnosable form of Dissociative Identity Disorder (Carlson, 1993). Furthermore, about 15% of the patients diagnosed with DID score below 20 on the DES. In a similar study, DES scores were compared to scores on other instruments administered to a non-clinical sample of college students. This sample was broken into 20 high scorers and 22 low scorers on the DES. The high and the low scorers differed significantly on all phases among several different measures including the DDIS, the SCL-90, and the MCMI. B It was therefore concluded that the DES quite accurately was able to predict those who will and those who will not have a dissociative disorder (Ross, 1991). Van Ijzendoorn and Schuengel have also studied the reliability of results obtained by the DES. In a metaanalysis of over 100 published studies they found that the DES was quite accurate in predicting dissociative disorders. Their results showed that in 30 studies with a total of 827 individuals diagnosed with dissociative disorders there was a mean DES score of 45.1. Compared to 811 subjects diagnosed with personality disorders with a mean DES score of 18.0 (Ross, 1996).

Another tool in the assessment of dissociative disorders and dissociative amnesia is a structured clinical interview. The Structured Clinical Interview for DSM-III Dissociative Disorders (SCID-D) developed by Steinberg has recently been updated to conform to DSM-IV criteria. This instrument involves over 250 items and can be tailored to suit the clinicians needs depending on the presentations of the subject. The procedure enables the clinician to use the interviewee’s verbal and non-verbal responses to rate the existence and severity of five DSM dissociative disorders: Psychogenic Amnesia, Psychogenic Fugue, Depersonalization Disorder, Multiple Personality Disorder, and Dissociative Disorder Not Otherwise Specified (Carlson, 1994).

This measure has been shown to be quite reliable in the assessment of dissociative disorders. Specifically, reliability rate for symptom scales have ranged from .60 to .95, with a .96 agreement between interviews for the presence or absence of dissociative disorders. The SCID-D was able to distinguish dissociative disordered from non-dissociative disordered patients and from normal controls at better than the .0001 confidence level, with almost no overlap of scores between the groups (Carlson, 1994).

A third tool for assessment was developed by Ross, Heber, Norton, and Anderson in 1989. The Dissociative Disorders Interview Schedule is a 131-item measure which requires yes/no responses by the interviewee. In addition to questions about dissociation, the DDIS includes an evaluation of childhood physical and sexual abuse, as well as other trauma related features such as Schneiderian first-rank symptoms, somatic complaints and paranormal experiences (Carlson, 1994). In many studies the DDIS has shown an overall interrater reliability of .68. This measure has shown to be extremely reliable and has a false positive rate of about 1% for MPD in the clinical population (Ross, 1994).

The final measure discussed here was developed by Loewenstein in 1991. This is a semistructured interview known as the Office Mental Status Examination for Complex Dissociative Symptoms and Multiple Personality Disorder. This interview involves a wide range of questions covering a broad spectrum of clinical presentations. The interview questions are grouped into the following symptom clusters: affective symptoms, somatoform symptoms, amnesia symptoms, autohypnotic symptoms (e.g. spontaneous trances) and process symptoms (i.e. signs of state and identity changes) (Carlson, 1994). This interview is also one of the few which systematically measures trauma and PTSD-like symptoms in an overall and comprehensive framework. While the reliability for this measure has yet to be conclusively studied, it is believed to be a highly useful tool. Once again, however, Loewenstein’s interview is not meant to be administered as a basis for diagnosis, but rather as a screen and alert to possible pathology.

All of these instruments have been shown to be fairly if not highly reliable measures for dissociative disorders. While some specifically cluster symptoms in order to determine the presence of dissociative amnesia, others do so in a more general manner. In the end it is up to the clinician as to how the symptoms would be best represented. Again, it cannot be overemphasized that these measures are in no way intended to provide a diagnosis. These measures are intended to facilitate exploration by the clinician into key areas found to be of significance. The decision of which measure to utilize will depend upon the particular needs and resources of the clinician or researcher (Carlson, 1994).

Of course, the most important factor as always is the relationship established between the clinician and the patient. None of these assessment tools are worth anything if the clinician is unable to effectively interact with the patient in a meaningful way. As with any other assessment and treatment program, rapport is of paramount concern. However, patients believed to have dissociative disorders are a special challenge. Issues of privacy, control, and trust that are often raised in the assessment process can be particularly intense for a traumatized patient who has experienced physical or sexual abuse, helplessness, and betrayal (Carlson, 1994). To compound this, patients with dissociative disorders has normally been conditioned by society to hide their experiences to avoid stigmatizing labels. Therefore, the use of a structured assessment may not only create a severe sense of anxiety for the patient but may also lead to inaccurate responsesas to not “force” the patient to recall painful past experiences while still gathering the necessary information to make an accurate assessment.

For dissociative disordered patients who are assessed during times when their adjustment is fragile or deteriorating, concerns about safety, and of not precipitating further disorganization, should be paramount to the therapist (Carlson, 1994). Again, most of these patients have become accustomed to ignoring the pain from past experiences and refusing to deal with the memories. When subjected to a test that probes these very experiences it is difficult to predict how the patient will react. The patient can become quite explosive and angry immediately or may have a delayed reaction, ruminating over the experiences silently for a long period of time. It is the duty of the clinician to be prepared for the possible reactions that may occur. Such experiences of dyscontrol can be minimized by helping the patient to focus, in an anticipatory fashion, on his or her affective style (Carlson, 1994). Again, dissociation is viewed as a psychological defense, any attempts to evade these defenses should be done with extreme caution.

Treatment of Dissociative Amnesia

There are different ways in which clinicians may go about treating dissociative amnesia. As discussed earlier, the view of dissociation that one holds is going to be a very important factor is treatment. Those supporting a psychobiological view may elect to use a pharmalogical treatment plan involving drugs intended to reduce the levels of nuerochemicals in the brain. Surgical procedures may also be implemented if the cause of the disorder is thought to be a physical problem such as insufficient bloodflow in the brain. This is not to say, however, that other cognitive efforts may not be undertaken together with or in place of these treatments. It has been found, in fact, that the best treatments typically involve a multi-faceted approach.

According to some views the heart of much of the treatment of dissociative disorders and dissociative amnesia in particular is long term psychodynamic/cognitive psychotherapy facilitated by hypnotherapy (Turkus, 1991). As stated earlier, hypnosis has been shown to be highly correlated with dissociative amnesia, and has been shown to be quite effective in aiding in recall of “amnesic events”. From this view there are several stages to an effective treatment plan. The first stage, which is tied together with the assessment phase, encompasses a span of time which is far longer than the first few sessions of testing. Once a careful and detailed assessment of all relevant past history is completed (which can takes anywhere from days to weeks), the therapist and patient jointly develop a plan for stabilization (Turkus, 1991). This phase revisits the point that dissociative patients are about to embark on a very stressful journey and therefore should be well prepared by the clinician for the possible hardships that may lie ahead. During this time the clinician and patient careful explore possible avenues for treatment including individual psychotherapy, group therapy, expressive therapies (art, poetry, movement, psychodrama, music), family therapy (current family), psychoeducation, and pharmocotherapy (Turkus, 1991). Expressive modalities are utilized to develop self awareness, recover traumatic memories, and work through painful affects (Ross, 1991). Psychoeducation is used to provide insight for the patient into his or her disorder. The hope is that through active involvement and better understanding the patient will gain a better perception of the situation and avoid self-stigmatization which can impede treatment. Treatment strategies for victims of abuse provide special difficulties as mentioned. The Empowerment Model, developed by Turkus, Cohen, and Coutois in 1991, is used for the treatment of the survivors of childhood abuse, and can be adapted to outpatient treatment. This strategy uses ego-enhancing, progressive treatment to encourage the highest level of function (“how to keep you life together while doing the work”) (Turkus, 1991).

The next stage of treatment normally involves the revisiting of the trauma experienced by the patient. This is normally the most difficult stage of treatment in dissociative disorders for it involves the reawakening of past, long repressed, pain. This may involve abreactions, which can release pain and allow dissociated trauma back into the normal memory track. An abreaction may be described as the vivid re-experiencing of a traumatic event accompanied by the release of related emotion and the recovery of repressed or dissociated aspects of that event (Turkus, 1991). Normally, treatment involves the use of planned abreactions to facilitate a smooth flow at key junctions in the treatment process. The important aspect is that both the patient and the clinician be at a point when they are prepared to confront this sudden release of information. One of the best ways to retrieve these memories has been though the use of hypnosis. The patient is asked to allow him or herself to slip into a hypnotic state wherein the traumatic event is relived in detail. Once these memories are tapped and brought into the open the clinician and patient work together to find a suitable means by which to deal with these memories.

This leads to the final phase of treatment which is the continued processing of traumatic memories and cognitive distortions, and further letting go of shame (Turkus, 1991). It is during this phase that a virtual rebuilding should take place. The patient is guided to the use of more effective mechanisms for dealing with the traumatic event or events and aided in the self-acceptance of his or her feelings. This process can be as long or as short as the patient and clinician are able to work through it, but it is important that the rebuilding not be rushed. There are often important life choices to be made about vocation and relationships at this time, as well as solidifying gains made from treatment (Turkus, 1991). Once again it is of utmost importance that the patient be allowed ample time to deal with and accept these new found memories and emotions. While after a period of time the formal treatment done between the clinician and the patient may be terminated, the true healing is a life-long process which may never truly be complete and a periodic revisiting may be necessary.

Conclusion

Dissociative Amnesia is a complex and little understood disorder. The processes by which this phenomenon occurs is highly debated and discussed by researchers and clinicians alike. Differing views and schools of thought provide very different ways of looking at and dealing with Dissociative Amnesia and dissociative disorders in general. In all we have seen the relative importance of identifying the lens with which we view this disorder and the impact which that view has upon our conceptualization and treatment. Furthermore, this differentiation in views makes the assessment and diagnosis dissociation just as difficult. Many of the tools developed, while quite useful and accurate in predicting the presence of dissociative symptoms, still ultimately rely upon the judgement of trained clinicians to recognize characteristics and provide a diagnosis. In all, while we have come quite far in the field, we still have a way to go.