Imagery Rehearsal Therapy for Nightmares
Nightmares are a cardinal symptom of PTSD and can also manifest as an isolated symptom or disorder, even in the absence of PTSD. Nightmares can significantly impair sleep quality and quantity and lead to daytime distress and impaired functioning (Harb, Phelps, et al., 2013). These impairments can exacerbate the problems of patients suffering from PTSD, such as depleted physical health, employment and relationship problems, poor adherence to treatment, and substance abuse. Disrupted sleep is also linked to the development and maintenance of PTSD, often creating a feedback loop between nightmares and PTSD (Nappi, Drummond, and Hall, 2012). IRT—a cognitive-behavioral treatment—has garnered significant interest among clinicians and researchers because of its ability to reduce nightmare frequency and intensity (Harb, Phelps, et al., 2013).
Treatment of nightmares with IRT involves having the patient describe a distressing dream and then repeatedly (over the course of treatment) rehearse a new dream with more desirable and less distressing content (Krakow et al., 1995). For example, a war veteran could alter a nightmare involving a firefight by "rehearsing" a new dream in which the enemy soldiers have harmless toy guns or creating an entirely new dream that has little, if any, resemblance to the original nightmare content. The process of rehearsing the new dream is believed to help patients assert control over their dreams and create a new association between sleep and pleasant or non-distressing dreams versus nightmares. This new association often reduces the frequency of nightmares, as well as the distress and arousal associated with them (Forbes, Phelps, and McHugh, 2001).
IRT Application to Military Populations and Evidence of Effectiveness
The use of IRT has been shown to be effective in seven studies with U.S. service-members and veterans (Cook et al., 2010; Forbes, Phelps, and McHugh, 2001; Harb, Thompson, et al., 2012; Lu et al ., 2009; Nappi et al., 2010; Moore and Krakow, 2007; Long et al., 2011). Appendix C, Table C.2, describes these studies and their results. Overall, the results from these efforts show that IRT can be effective in reducing nightmare frequency and intensity among veterans with combat-related PTSD and recurring nightmares. Effect sizes for changes in nightmare frequency in these studies ranged from 0.45 to 1.37. One study showed that IRT was effective when patients' symptoms were resistant to previous inpatient treatment programs (Forbes, Phelps, and McHugh, 2001). Additionally, Harb, Thompson, et al. (2012) showed that excluding violent details from a revised nightmare and incorporating a positive resolution tended to improve treatment outcomes in terms of nightmare frequency and sleep quality (B = 5.69 [SE = 1.14]).
The efficacy of IRT may not be limited to individual treatment delivery settings, as demonstrated by multiple studies that found significant positive results from IRT interventions in group settings (Long et al., 2011; Lu et al., 2009). However, Nappi et al. (2010) have shown that individual treatment delivery may foster greater effects than group delivery in terms of symptom severity reductions. Veterans in that study who were treated with individual IRT experienced significantly larger mean decreases in ISI scores (9.08) than those treated with group IRT (1.58). In addition to reducing nightmares, IRT may be effective in reducing other symptoms of PTSD and comorbid conditions, such as depression and insomnia (Forbes, Phelps, and McHugh, 2001; Nappi et al., 2010). One study observed effect sizes from IRT of 0.72 and 1.03 for ISI and PCL scores, respectively (Nappi et al., 2010). Additionally, the effects of IRT in reducing nightmares appear to be enduring. One study showed that nightmare frequency decreased from baseline by 40 percent and 37 percent at three- and six-month follow-ups after treatment, respectively (Lu et al., 2009). Finally, IRT may be useful in treating servicemembers with acute combat-related nightmares (Moore and Krakow, 2007).
Summary and Limitations of IRT
Several of the studies on IRT in servicemember populations show promising results; however, as with CBT-I studies, the current evidence base is limited by small sample sizes and a lack of control groups. With two exceptions (Cook et al., 2010, and Nappi et al., 2010), IRT studies had sample sizes of less than 50 and did not use control conditions. Additionally, the majority of the studies focused primarily on Vietnam veteran samples, with current servicemembers used in only one pilot study (Moore and Krakow, 2007). Given the differences in combat experiences and the generation gap between Vietnam and OEF/OIF veterans, clinicians may need to modify IRT procedures when working with veterans of a specific conflict to achieve better outcomes. Veterans may also feel uncomfortable participating in group therapy with veterans from eras other than their own, making mixed-generation treatment groups inappropriate and less effective. Clearly, there is a need for more research on the use of IRT in treating recent veterans and current servicemembers to identify treatment protocol modifications for this younger generation. Despite these limitations, the body of research involving IRT and veteran populations shows promising results. Overall, further research on IRT in the military health system and VHA is needed to develop best-practice guidelines for treating military members and veterans with recurrent traumatic nightmares.