Dreams and exposure therapy in PTSD

Journal of Traumatic Stress, Vol. 14. No. 3, 2001

Dreams and Exposure Therapy in PTSD

Barbara Olasov Rothbaum'*' and Thomas Alan Mellman2

Exposure therapy is a well-established treatment for PTSD that requires the patient to focus on and describe the details of a traumatic experience. Nightmares that refer to or replicate traumatic experiences are prominent and distressing symptoms of PTSD and appear to exacerbate the disorder: With this apparent paradox in mind, exposure therapy and the literature on sleep and PTSD are reviewed in the context of the relationship between therapeutic exposure and exposure to trauma- related stimuli that occurs in dreams. It is concluded that nightmares that replay the trauma and disrupt sleep do not meet requirements for therapeutic exposure, whereas other dreaming may aid in the recovery from trauma. KEY WORDS: PTSD exposure therapy; dreams; sleep; REM sleep; trauma.

Are dreams following a traumatic event a form of therapeutic exposure? In individuals recently traumatized, can dreams function as a form of working

through the trauma and decrease posttraumatic stress disorder symptoms? In PTSD sufferers, why do their dreams of the incident appear to exacerbate their

symptoms?

These are the questions that prompted this discussion paper. F'TSD sufferers have no refuge: they feel haunted by their experiences day and night. By day, they often experience intrusive recollections, anxiety, and may feel danger is lurking around every comer (Rothbaum, Foa, Riggs, Murdock, & Walsh, 1992). Rather than being able to take solace in a good night's sleep in the comfort of their own bed, they are often haunted by their dreams, coming to fear the nighttime for the vulnerability they fear in the dark with their eyes open or shut (Foa & Rothbaum,

'Department of Psychiatry and Behavioral Sciences. Emory University School of Medicine, Atlanta, Georgia.

'Department of Psychiatry, Dartmouth Medical School, Lebanon, New Hampshire. 'To whom correspondence should be addressed at Department of Psychiatry and Behavioral Sciences, The Emory Clinic, I365 Clifton Road, Atlanta, Georgia 30322; e-mail: [email protected].

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08W-9867x)1/0700W81519.HyI 0 2001 Inkmotional Society for Tmvmvic SIP%= Studies

482 Rothbaum and Mellman

1998; Neylan et al., 1998). How can we, as mental health professionals, help them to achieve recovery that includes a restful night’s sleep? Herein, exposure therapy, sleep, and dreaming as they apply to PTSD will be briefly reviewed, and relationships between exposure to trauma-related stimuli in dreams and nightmares and therapeutic exposure will be explored.

A brief overview of exposure therapy is presented here. The reader is referred to Foa and Rothbaum (1998) for an extensive discussion of exposure therapy for PTSD or to Rothbaum and Foa (1999) for a brief overview of the research on exposure therapy for PTSD.

Exposure Therapy

A variety of terms have been used to describe prolonged exposure to anxiety- provoking stimuli. These include Flooding/ImaginalAn Vivo/Prolonged/Directed; in this paper, these are referred to collectively as exposure. Exposure methods share the common feature of confrontation with frightening, yet realistically safe, stimuli that continues until the anxiety is reduced. By continuing to expose oneself to a safe yet frightening stimulus, anxiety diminishes, leading to a decrease in escape and avoidance behavior that was maintained via negative reinforcement (Mowrer, 1960).

In imaginal exposure for PTSD, patients confront their memories of the traumatic event. Some imaginal methods (e.g., Foa. Rothbaum, Riggs, & Murdock, 1991; Foa & Rothbaum, 1998) involve the patient’s discussing the trauma in detail in the present tense for prolonged periods of time (e.g., 45-60 min), with prompt- ing by the therapist for any omitted details. Other forms of imaginal exposure (e.g., Cooper & Clurn, 1989; Keane, Fairbank, Caddell, & Zimering, 1989) involve the therapist’s presenting a scene to the patient based on information gathered prior to the exposure exercise. The duration and number of exposure sessions have also var- ied, sometimes within the same study. Details on the implementation of exposure for PTSD have been provided in Foa and Rothbaum (1998).

It has been suggested that PTSD emerges due to the development of a fear network in memory, which elicits escape and avoidance behavior (Foa, Steketee, & Rothbaum, 1989). Mental fear structures include stimuli, responses, and meaning elements. Anything associated with the trauma may activate the fear structure. The fear network in people with PTSD is thought to be stable and broadly generalized so that it is easily accessed. Emotional processing theory (Foa & Kozak, 1986) proposes that successful therapy involves correcting the pathological elements of the fear structure, and that this corrective process is the essence of emotional processing. Two conditions have been proposed to be required for fear reduction. First, the fear structure must be activated. Second, new infomation must be provided that includes elements incompatible with the existing pathological elements so they can be corrected. Exposure procedures consist of confronting the patient

Dreams and Exposure Therapy 483

with trauma related information, thus activating the trauma memory, and keeping the patient exposed to the memory for a prolonged period of time. This prolonged activation allows any corrective information to be integrated, and thus modify the pathological elements of the trauma memory. In support of this model is a study demonstrating that fear activation during treatment promotes successful outcome (Foa, Riggs, Massie, & Yarczower, 1995).

Several mechanisms are thought to be involved in the specific changes rel- evant to improvement of PTSD. First, repeated imaginal reliving of the trauma is thought to promote habituation and thus reduce anxiety previously associated with the trauma memory and correct the erroneous idea that anxiety stays forever unless avoidance or escape is realized. Second, the process of deliberately confronting the feared memory blocks negative reinforcement connected with the fear reduction following cognitive avoidance of trauma related thoughts and feelings. Third, reliving the trauma in a therapeutic, supportive setting incorporates safety information into the trauma memory, thereby helping the patient to realize that remembering the trauma is not dangerous. Fourth, focusing on the trauma memory for a prolonged period helps the patient to differentiate the trauma event from other nontraumatic events, thereby rendering the trauma as a specific occurrence rather than as a representation of a dangerous world and of an incompetent self. Fifth, the process of imaginal reliving helps change the meaning of FTSD symptoms from a sign of personal incompetence to a sign of mastery and courage. Sixth, prolonged, repeated reliving of the traumatic event affords the opportunity for focusing on details central to negative evaluations of themselves and modifying those evaluations (Foa & Rothbaum, 1998).

Therapeutic exposure requires long, repeated exposures that allow for the mechanisms listed earlier to be enacted. The simplest and most straightforward mechanism is probably habituation, which describes decreased responding to the same stimulus when it is presented repeatedly over time. Short exposures may further sensitize, actually making the fear worse. For example, consider a child who is fearful of dogs following a dog bite. A typical in vivo (in real life) exposure program might involve the child first being exposed to small fluffy nonthreatening dogs at a distance, but remaining in that situation long enough for her fear to decrease, allowing time for the child to see the animal poses no threat to her. Exposure would continue by increasing the size of the dog, decreasing the distance from the dog, and increasing the similarity to the appearance of the dog that bit her. In all cases, she must be allowed to stay near the animal until her fear decreases to recognize that the animal poses no threat to her. If she is exposed to a dog, experiences fear, and the dog is removed while she still feels fear, her fear would be expected to be strengthened. She would not be able to convince her body that she did not narrowly escape another attack. Her body would respond with fear in the presence of the dog and would experience relief upon the removal of the dog. This is not a therapeutic exposure.

484 Rothbaum and Mellrnan

Now we present a brief overview of normal sleep with attention to REM sleep and dreaming, and observations that have been made in relation to PTSD.

Normal Sleep

There have been considerable advances in the understanding of the mechanisms and function of sleep. However, certain key questions remain unresolved. Advancing knowledge and continuing uncertainty particularly apply to understanding of the nature and function of rapid eye movement or REM sleep, the “active” stage of sleep that is most specifically associated with dreaming. Many current insights into sleep, including the discovery of REM sleep approximately 50 years ago, have come from the application of electroencephalographic or EEG recording, the method for measuring elecmcal activity of the brain. Modem tech- niques for obtaining EEG and other physiological data during sleep are referred to as polysomnography or PSG.

During normal sleep, arousal continues to diminish after sleep is initiated, and this process is indexed by EEG waves that gradually exhibit slower oscillation and higher voltage (slow wave sleep). After a 1-2 hr period of deepening non-REM sleep, cortical arousal increases, heralding the onset of the first REM period. REM sleep is characterized by relatively fast, desynchronized low voltage EEG activity (similar to the wake state or light sleep), rapid eye movements that appear similar to eye movements recorded while an awake individual is looking around at the environment, and diminished peripheral muscle tone. E M sleep is sometimes referred to as paradoxical sleep due to the increased cortical arousal occumng during sleep, in conjunction with diminished peripheral motor tone. Approximately four to five non-REh4REM cycles occur across the normal sleep period with less slow wave sleep, and increased duration and intensity (e.g., frequency of eye movements) of REM sleep as the night progresses.

The relationship between REM sleep and dreaming has primarily been established by experiments in which participants were awakened out of REM and other sleep stages and asked to relate what was on their mind just prior to awakening. Although dreaming is not restricted to REM sleep, these studies document that the most “dream-like” of mental activity occurs during REM sleep (Foulkes, 1962). In contrast to typical waking thought, dreams tend to feature suspension of logic and plausibility, unclear chronology, and disparate references that are often linked by emotional themes. Recent data from functional brain imaging studies suggest that this pattern of mentation is associated with a neuroanatomical pattern of brain activation that is distinct from what occurs during conscious awakening (Hobson, Stickgold. & Pace-Schott, 1998). Most dreams are not available for conscious recall unless they occur just prior to an awakening, an effort is made to recall the dream, or the dream has a high degree of emotional salience.


Although a comprehensive discussion of the function of E M sleep and dreaming is beyond the scope of this review, the evidence for REM sleep facil- itating certain kinds of learning and relating to emotional adaptation may be of relevance to PTSD. The process by which recognition or performance improves after the last training or exposure to a learning task is referred to as consolidation. Studies have demonstrated that disrupting REM sleep interferes with consolidation of recently learned patterns or procedures (Karni, Tanne, Rubenstein, Askenasy, & Sagi, 1994; Smith, 1995). Other research has documented associations of early onset and intense REM activity during a distressing and disruptive life event (divorce) with lower rates of depression in the subsequent year. These investigators suggested that REM sleep and dreaming facilitate emotional adaptation as a consequence of activation and integration of recent and remote memory networks (Cartwright & Lloyd, 1993). The opportunity for memories of threatening experiences to be activated in a state of muscular relaxation and to be integrated with other memory networks during REM sleep would seem analogous to aspects of exposure therapy. In this regard, Hartmann (1998) has postulated that an adaptive function of dreaming following trauma and dreams in general may be to extend associative memory networks.

Sleep in PTSD

Most clinicians would agree, and the DSM-IV symptom criteria (American Psychiatric Association, 1994) for the disorder reflect, that distressing nightmares and difficulty in initiating and maintaining sleep are common complaints among those suffering with PTSD (Rothbaum et al., 1992). For example, "trouble sleeping" was the most common symptom endorsed by disaster survivors (Green, 1993) and in 9 1% of veterans with PTSD surveyed (Neylan et al., 1998). The presence of sleep disturbances would seem to have further implications for trauma survivors. If deprived of adequate sleep, one would expect the trauma survivor to be more sensitized by, reactive to, and therefore more avoidant of exposures to reminders of the trauma whereas a well-rested state would enhance an individual's capacity for coping.

Nightmares that refer to or replicate traumatic experiences have been empha- sized as a cardinal symptom of PTSD (Ross, Ball, Sullivan, & Caroff, 1989). The relationship of trauma related nightmares and PTSD has been supported by studies that retrospectively examined dream content among trauma-exposed subjects with and without the disorder (Neylan et al., 1998; Van der Kolk, Blitz, Bun; Sheery, & Hartmann, 1984).

In a recent investigation led by the second author (TAM) at the University of Miami, dream content elicited by morning diaries and PTSD status were as- sessed in subjects with recent traumatic injuries. Injured patients who recorded dream reports that were similar or identical to the recent traumatic experience had


significantly greater PTSD severity than patients whose dreams did not specifically depict the incident or patients who did not recall dreaming. There was also a trend for dreams with “replicative” tendencies at the initial assessment to be associated with PTSD at follow up 2 months after the trauma. Four of the participants with trauma-replicating dreams and initial PTSD symptoms provided subsequent dream reports. Among the two who ultimately recovered from FTSD, intervening dream content was no longer rated by the subject as similar to the traumatic experience. In the two cases where PTSD symptoms persisted, subsequent dreams continued to represent the actual events of the trauma. These observations further support the notion embedded in the DSM-IV, that the continuing experience of dreams that closely resemble a traumatic event mark a symptomatic and maladaptive emotional response. Consistent with the aforementioned integrative functions posited for dreaming, many of the dreams that did not directly depict the trauma did, however, contain references to it, and several depicted threatening, albeit nonrealistic scenarios (Mellman, David, Bustamante, Torres, & Fins, 2001).

With respect to the other FTSD symptom criterion in the DSM-IV refemng to sleep, laboratory studies are mixed as to the presence of moderate versus no significant impairment in sleep initiation or maintenance (Mellman, Nolan, Hebding, Kulick-Bell, & Dominguez, 1996; Dow, Kelsoe, & Gillin, 1996; Ross et al., 1994a; Hurwitz, Mahawold, Kuzkowski, & Engdahl, 1998). A limitation of these studies is that almost all of the data come from male war veterans with very chronic PTSD with assessments made in the perceived safe environment of the sleep laboratory. There is support from this literature for more active REM sleep (i.e., increased frequency of eye movements within REM periods) as well as the suggestion of more frequent motor activation during, and symptomatic awakenings arising from, REM sleep in patients with PTSD than those without PTSD (Ross et al., 1994b; Mellman et al., 1996). The aforementioned study involving acutely traumatized subjects with injuries (Mellman et al., 2001) includes a subset of individuals receiving PSGs. These data from 21 injured subjects and 10 noninjured controls preliminarily suggest more frequent disruption of REM sleep (entries of the wake state) but not other sleep stages among those who are developing PTSD. Although more data are needed for definitive interpretation, these observations from the acute aftermath of trauma can be viewed as being consistent with the theories suggesting a role for REM sleep and dreaming in emotional adaptation via integration of distressing memories (Cartwright & Loyd, 1993; Hartmann, 1998). It may be that the inferred activation of unaltered trauma memories in dreams with disruption of the REM sleep state could interfere with potentially adaptive memory processing and serve to enhance accessibility of the trauma memory.

Thus, we have some information for two of the initial questions: In recently traumatized individuals, are their dreams a form of working through the trauma that can decrease their PTSD symptoms? Can dreams following a traumatic event act as a form of therapeutic exposure? The data presented above indicate that this

Dreams and Exposurr Therapy 487

is not necessarily the case. Survivors who report dreams that closely resemble their traumatic events are more likely to be manifesting PTSD. Survivors who reported no dreaming, dreaming unrelated to the traumatic event, or dreams that incorporated a reminder of the traumatic event but in a way that was integrated with other content were less likely to manifest PTSD symptoms. The conditions by which dreams can become more integrative or nondisruptive or both to sleep may be when REM sleep is more adequately maintained. Conversely, integrative, less realistic, and less frightening dreams may not be as disruptive to sleep.

Dreams and Therapeutic Exposure

Often when exposure therapy is first explained to a PTSD sufferer, they respond to the therapist by explaining that they already think about the trauma and dream about it frequently. If exposure works, why hasn’t their frequent exposure been therapeutic? In PTSD sufferers, why don’t their dreams of the incident act as a form of therapeutic exposure and decrease their symptoms?

Distressing dreams that replay the traumatic event and provoke awakening do not appear to provide a therapeutic exposure. Reasons could include that the dreams are not of sufficient duration to allow for habituation to occur. Very often the sufferer awakes temfied, which may tend to sensitize further. In addition, the experience of dreams or nightmares often feels real. This is a different experience from imaginal exposure to the memory of the trauma. Even though the patient is asked to relive the memory of the trauma and to recount it in the present tense as if it is happening now, it is clear it is just a memory. In contrast, in dreams, there is often not this realization. It feels as if we are being chased, about to be caught, possibly killed. When the dreamer awakes, it is often with the sensation of having narrowly escaped danger. Thus, these dreams may serve to sensitize, actually increasing the fear, rather than acting as therapeutic exposures. In terms of emotional processing theory, the fear memory has been activated (Condition I), but corrective information was not incorporated (Condition 11). Interestingly, a procedure that has been applied to nightmares in nightmare sufferers (Krakow, Kellner, Neidhardt, Pathak, & Lambert, 1993), teaches the patient to think of their nightmares but with an alternative ending. In this case, when successful, corrective information may be incorporated, thus satisfying the second proposed condition required for successful emotional processing.

We can examine dreaming following trauma in relation to the presumed mechanisms by which exposure therapy achieves its therapeutic effects. First, as mentioned above, repeated imaginal reliving of the trauma is thought to promote habituation. As noted, dreaming trauma-related material is often reported with awakening in an agitated state, which would not lead to habituation but rather to sensitization. Second, the process of deliberately confronting the feared memory in exposure therapy blocks negative reinforcement connected with the fear reduction following cognitive avoidance of trauma-related thoughts and feelings. As the


dreamer is NOT deliberately confronting the memory in dreams and in fact may avoid sleep to avoid dreaming, this negative reinforcement paradigm remains in place unchecked. Third, reliving the trauma in exposure therapy in a therapeutic, supportive setting incorporates safety information into the trauma memory, thereby helping the patient to realize that remembering the trauma is not dangerous. Just the opposite is true for nightmares about the trauma. As discussed earlier, the threat in the dream may feel real, and the dreamer may wake feeling she has just narrowly escaped death, which confirms the threatening nature of the traumatic material. Most PTSD sufferers do not report feeling safe in the dark in the middle of the night, either. Fourth, focusing on the trauma memory for a prolonged period in exposure therapy helps the patient to differentiate the trauma event from other nontraumatic events, thereby rendering the trauma as a specific occurrence rather than as a representation of a dangerous world and of an incompetent self. In nightmares, the exposure is of insufficient duration, is sufficiently threatening, and demoraliz- ing that the person may feel like they are not being able to cope day or night. Fifth, the process of imaginal reliving in exposure therapy helps change the meaning of PTSD symptoms from a sign of personal incompetence to a sign of mastery and courage. In contrast, the fear of the nightmares and fear of sleeping may be taken as a further sign of weakness. Lastly, prolonged, repeated reliving of the traumatic event in exposure therapy affords the opportunity for focusing on details central to negative evaluations of themselves and modifying those evaluations. This does not occur with nightmares that are predominantly replications of the trauma.

In summary, it seems evident that the mechanisms by which exposure therapy is presumed to achieve therapeutic benefits are not operating with the exposures provided by nightmares that replicate trauma and disrupt sleep. In fact, it may be that these exposures are sensitizing and serve to maintain aspects of PTSD. There is evidence, however, supporting the possibility that dreams can serve adaptive functions following trauma and other distressing life events. It would seem that dreams that are more integrative in nature (i.e., incorporate trauma and nontrauma related references) and less disruptive to sleep would have a greater likelihood of enhancing emotional recovery or at least are associated with recovery. Recent evidence suggests that a variant of therapeutic exposure targeting dream content is beneficial to individuals suffering with PTSD (Krakow et al., 2000). Other consid- erations include educating patients about nightmares and healthy sleep habits and appropriate utilization of medication to reduce sleep disruption. It is recommended that clinicians and researchers pay more attention to the effects of nightmares and that future research explore the issues raised in this discussion.

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Dreams and exposure therapy in PTSD