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
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@example.com.
08W-9867x)1/0700W81519.HyI 0 2001 Inkmotional Society for Tmvmvic SIP%= Studies
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1998; Neylan et al., 1998). How can we, as mental health professionals, help them to achieve recovery that includes a restful nights 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.
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 trau- matic event. Some imaginal methods (e.g., Foa. Rothbaum, Riggs, & Murdock, 1991; Foa & Rothbaum, 1998) involve the patients 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 therapists 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 pro- cessing. Two conditions have been proposed to be required for fear reduction. First, the fear structure must be activated. Second, new infomation must be pro- vided that includes elements incompatible with the existing pathological elements so they can be corrected. Exposure procedures consist of confronting the patient
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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 con- fronting 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 re- membering 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 de- tails 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.
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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.
There have been considerable advances in the understanding of the mecha- nisms and function of sleep. However, certain key questions remain unresolved. Advancing knowledge and continuing uncertainty particularly apply to under- standing 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 estab- lished 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 re- call 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.
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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 on- set 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 ac- tivated in a state of muscular relaxation and to be integrated with other memory networks during REM sleep would seem analogous to aspects of exposure ther- apy. 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 sleep- ing" 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
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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, interv...