|In the Mind’s Eye of the Beholder|
Imagery rehearsal therapy is a broad term for myriad cognitive-imagery treatments for chronic and potentially acute nightmare disorders. Several groups are researching specific brands of the therapy, and this modality is receiving substantial attention in two converging ways.
First, several review articles have argued that imagery rehearsal therapy (IRT) is now or is becoming a first-line treatment for chronic nightmare disorder (CNS Drugs 2006;20:567-90 and Sleep Med. Rev. 2006;10:19-31).
Second, media coverage of the rising rates of posttraumatic stress disorder (PTSD) in U.S. military personnel has raised public awareness of the interaction between chronic nightmares and traumatic exposure.
All IRT programs stress imagery rehearsal of consciously altered dream content. But they vary on the use of exposure therapy, which involves intense focus on the content of nightmares and the trauma event.
A recent report in this publication about an IRT program conducted at Yale University, New Haven, Conn., for Vietnam War veterans might have given the impression that the therapy requires a large exposure element, because “patients are asked to identify a repetitive nightmare related to a traumatic event” (“Revised Imagery Protocol May Help Some Vets,” April 2009, p. 10). However, that was not what my coinvestigators and I intended when we developed the most tested and widely published version of IRT ( JAMA 2001;286:537-45).
Since 2000, our continuing work at the Sleep & Human Health Institute, Albuquerque, has focused on a two-component IRT protocol, both of which eschew any substantive discussion of trauma or the traumatic content of nightmares (Behav. Sleep Med. 2006;4:45-70).
Each component targets a distinct but related problem in the nightmare sufferer. The first addresses nightmares as a “learned sleep disorder,” and the second addresses them as “the symptom of a damaged or malfunctioning imagery system.” The therapy comprises four 2-hour sessions for groups—or for individuals, just a few hours.
In the first two sessions, patients are encouraged to recognize the impact nightmares have on their sleep by discussing how nightmares promote learned insomnia. Then they are taught to recognize how nightmares can develop into a learned behavior. In the last two sessions, patients are encouraged to explore the human imagery system, monitor how this system operates, appreciate connections between daytime imagery and dreams, and then implement the specific steps of IRT—that is, selecting a nightmare, changing the nightmare into a new dream, and rehearsing the new dream.
We never discount patients’ perspectives on the triggering incidents that they perceive as the source of their nightmares, because trauma survivors often assume nightmares are an unalterable aspect of PTSD that may have purpose or meaning.
Nevertheless, they are taught that nightmares can be effectively treated as a distinct sleep disorder without any discussion or emphasis on previous traumatic events or nonsleep-related PTSD symptoms. As such, our brand of IRT seeks to minimize exposure elements; patients are instructed to avoid working with replaylike dreams of traumatic events.
Our treatment strategy focuses on the “nightmaring process” and not simply on nightmares. When individuals appreciate that nightmares might be a learned sleep pattern and they reestablish confidence in the use of their natural imagery skills, disturbing dreams and nightmares abate.
The dramatic potency of exposure therapy for PTSD proper is well recognized, but I remain skeptical of nightmare treatments that combine the two approaches (exposure and IRT). Nightmare patients are skittish about seeking treatment for this vexing problem; frequently express embarrassment or, worse distress, when discussing the problem; often drop out of treatment; and in so doing, reinforce avoidance behavior. The addition of exposure components to IRT can exacerbate these problems in some (certainly not all) nightmare patients; whereas other versions of IRT can— and have—achieved marked successes without major exposure elements.
On the related matter of sleep in PTSD, since 1997 my coinvestigators and I have published and presented data on the complexity of sleep disturbances in nightmare disorders, and we submit that disturbing dreams herald a deeply rooted sleep pathophysiology, often masquerading as classic psychiatric insomnia (Sleep Breath. 2002;6:189-202).
When we looked beyond insomnia and nightmares, we diagnosed extraordinarily high rates of obstructive sleep apnea (OSA) in more than 1,000 trauma survivors in clinical and research samples. At our clinic, we continue to document OSA rates of more than 80% in patients— most of whom have PTSD—who seek help for their nightmare complaints.
Anecdotally, this physiologic disorder of sleep respiration seems to play an undetermined role in the nightmaring process, perhaps through the effects of chronic sleep fragmentation and resultant sleep deprivation. This sleep fragmentation might compromise the natural human capacity for mental imagery, which in turn creates a vulnerability to onset and perpetuation of chronic nightmares.
Finally, in certain nightmare patients who are already suffering chronic and severe sleep fragmentation or deprivation from an occult and undiagnosed OSA condition, it is conceivable that exposure therapy produces an intolerable stress load that increases risk for worse outcomes.