In this issue of the Journal of Clinical Sleep Medicine, Creamer and colleagues address the prevalence of nightmares among active military members at a large academic Military Sleep Disorders Center.1 The authors should be commended for the outstanding article and for highlighting such an important topic. Many patients with nightmares avoid sleep to avoid their nightmares,2 perpetuating insomnia and adversely affecting daytime symptoms. Without treatment, nightmares are a risk factor for suicidal thoughts, and attempted and completed suicide, even after accounting for substance abuse, posttraumatic stress disorder (PTSD), and other mood disorders.3–7 Unfortunately, patients who experience nightmares rarely ask for help, and physicians tend to underdiagnose the condition, leading to a gap in care with potentially disastrous implications for individual patients.8–10 The persistence of nightmares and sleep disturbances in Vietnam veterans,11 and the finding that duration of sleep disturbance can increase suicide risk,5 should motivate us to do better.
In this retrospective review of 493 active duty military members, sleep intake questionnaires, electronic medical records, and polysomnography were used to delineate features of sleep disturbances among those with and without nightmares, as well as trauma-related nightmares (TRN). Most of the subjects in the current study had deployed to Iraq and Afghanistan (between 70% and 80%), and presented with excessive daytime sleepiness and insomnia. Selection bias inherent in the study design precludes an accurate assessment of prevalence. Similar to prior studies, the authors found that nightmares were underreported. Although only 3.9% referenced nightmares as the reason for their visit, 31.2% reported clinically significant nightmares on intake questionnaires. Significant differences were seen between subjects with nightmare disorder and TRN. Those with TRN were more likely to have deployed to combat and had greater severity of insomnia, with more traumatic brain injury, PTSD, depression, anxiety, and higher rates of obstructive sleep apnea (OSA) compared to those with nightmare disorder. It is impossible to sort out in a retrospective study whether the increased OSA in TRN is related to nightmare disorder or because the population is enriched with PTSD and traumatic brain injury, each strongly associated with OSA in military populations.12,13 The method for diagnosing and characterizing PTSD is critical, as patients may self-diagnose on clinic intake questionnaires, in the absence of an evidence-based diagnosis. Accuracy can be improved by basing diagnosis rates on behavioral health evaluations and by use of the PTSD Checklist (PCL). Military (PCL-M) and civilian (PCL-C) versions have been validated.14,15 This questionnaire is widely used in research, and can serve as a check on one population's degree of PTSD severity compared to others.
A more comprehensive review of medications is needed. Although only 16% of the population was using a prescription sleep aid prior to their consultation with the sleep clinic, it is likely that the rates of prescribed psychoactive medications were higher. Medications that treat mood disorders can affect sleep architecture and sleep-related symptoms. Prior research evaluating sleep disorders in the active-duty population have found significant polypharmacy with psychoactive medications.12,13 One recent review of this subject noted that out of a pool of more than 300,000 veterans from Iraq and Afghanistan, 8.4% were prescribed five or more psychoactive medications, with potential effects on overdose and suicidal ideation.16 Many service members arrive at our sleep clinic already on the alpha-1 receptor antagonist prazosin, initiated by a behavioral health provider or a primary care physician. A review of the medication list could help determine the percentage of subjects already being treated for nightmares, as well as highlight dosing adequacy.
This is not the first time that lack of attention to nightmares has been raised. Although nightmares can be frequent following traumatic experiences such as combat, and violent crime such as sexual assault, patients tend to underreport, or only do so when prompted on a questionnaire or during the interview. Although those with nightmares are interested in receiving medical care and information about nightmares, only one-third will seek help, and of those who seek help, only one-third will report to derive benefit.8,10,17–20 It is still not clear whether this barrier to care is based on patient perceptions about nightmares as a disorder or a normal part of wartime service, stigma about PTSD and nightmares, a lack of knowledge about who the correct specialist is to treat nightmares, or a lack of confidence in the medical system to help with this condition.
There are a number of reasons why the health care system fails this patient population. Many physicians do not understand the diagnostic criteria for nightmare disorder, or the therapeutic options. This could lead to physician avoidance during a clinic visit. Furthermore, the level of training on nightmares is variable in the sleep community. Historically, sleep medicine has been a multidisciplinary field. Prior to 1991, one-third of sleep specialists were neurologists, one-third were pulmonologists, and the remainder was split between psychiatry, PhDs, and other disciplines. By 2002 the specialty grew and more than one-half of sleep specialists are now pulmonologists.21 Until recently many sleep specialists obtained board certification without a dedicated sleep fellowship and the lack of standardization in training has very likely contributed to the problem.
Moving forward, research should emphasize a better understanding of true prevalence and risk factors for the development of nightmare disorder. The use of standardized nightmare questionnaires including the Nightmare Frequency Questionnaire22 and Nightmare Distress Questionnaire23 would be beneficial. The diagnosis of PTSD is challenging in retrospective sleep medicine research, but prospectively can be improved by use of the PCL-M (for military personnel) and PCL-C (for civilians).14,15 Similar to the evaluations by Phelps et al.24 and Mysliwiec et al.,25 research characterizing polysomnographic features should assess the presence of REM sleep without atonia and sleep architecture in proximity to in-laboratory nightmares.
This article should serve as (another) call to action to recognize nightmares as a marker of serious underlying sleep and behavioral health disturbances. Within the sleep community, continuing to develop expertise on this topic is critical. Forecasted shortages in sleep physicians and behavioral clinicians with this expertise will be a challenge. Outreach to referral sources should focus on stressing nightmares as an underdiagnosed condition and a risk factor for suicide in an already compromised population. Given the psychological stressors that accompany two decades of constant war in the Middle East and the growing prevalence of sleep disorders, service members represent an at-risk and underrecognized population for nightmares.
The authors report no financial conflicts of interest.
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