The National Comorbidity Survey estimates that approximately 50% of the population in the United States is exposed to traumatic events and that the lifetime prevalence of posttraumatic stress disorder (PTSD) is approximately 7.8%.1 Multiple studies have demonstrated that patients with PTSD complain of recurrent nightmares and sleep continuity disturbances, which are listed separately in the re-experiencing and hyperarousal clusters in DSM-IV.
Insomnia and nightmares
Sleep disturbances have been described in female rape victims as well as in a heterogeneous sample of women with PTSD.2,3 A study of 116 Vietnam veterans receiving treatment in a PTSD specialty clinic found that disturbed sleep (separate from nightmares) was the most frequently reported symptom (in 90% of participants).4 Recent data from soldiers returning from service in Iraq have shown that sleep disturbances and associated daytime fatigue were the most frequently reported symptoms in those with PTSD.5 Overall, there are ample data that sleep disturbances are a potent source of distress in patients with PTSD.6,7
Insomnia and other sleep disturbances occur frequently in patients with PTSD and they can be severe. Consequently, more than half of affected patients are treated with sedating antidepressants or sedative hypnotics.8
Recurrent nightmares are a signature feature of PTSD.9 Patients often report sleep phobia, in part because they dread the nightmares and the associated feeling of helplessness.6 Recurrent nightmares, sleep phobia, and chronic insomnia provide a strong conditioning context for associating the bedroom with anxious arousal. This becomes even stronger for sexual assault victims who may have experienced the traumatic event in the bedroom. Thus, patients with PTSD have difficulty in relinquishing a defensive posture that is critical for inducing normal healthy sleep.
Findings from objective studies using polysomnography show increased sleep continuity disturbances in patients with PTSD compared with controls. This was evidenced by decreased total sleep time, frequent arousals, particularly in rapid eye movement (REM) sleep, and increased motor activity during sleep. However, a few studies did not find differences in objective sleep measures among patients with PTSD and controls.10 The emerging evidence suggests that subjective complaints of sleep duration and sleep fragmentation are more prevalent and severe than the objective measures. This has raised the question of whether patients with PTSD have intact hypervigilance during light stages of sleep. This fits clinically with the frequent report from patients that they “sleep with one eye open.”
Consequences of disturbed sleep in PTSD
Disturbed sleep is associated with a wide range of adverse conditions. Subjectively, these include fatigue, cognitive impairment, mood disturbance, and reduced quality of life.11 Objectively, disturbed sleep has been associated with poorer job performance and increased frequency of accidents, aggression, and use of alcohol(Drug information on alcohol).12-14 Furthermore, there is a large body of evidence that demonstrates that chronic sleep loss is associated with poor psychomotor performance, especially when tasks require sustained vigilance.15 Compounding such effects is the inability of many sleep-deprived persons to self-monitor their sleepiness or performance deficits.16
Multiple prospective studies have found that disturbed sleep predicts future mood and anxiety disorders. Data from the NIMH Epidemiologic Catchment Area study show that insomnia predicts new-onset depression and anxiety disorder.17 Disturbed sleep is associated with increased substance use and abuse and major depressive disorder.14,18 Also, disturbed sleep and nightmares are associated with increased risk for suicide.19
In addition, disturbed sleep increases the risk of obesity, diabetes, impaired immunocompetence, hypertension, and cardiovascular disease. In a large survey of police officers, PTSD symptoms were significantly related to both somatic symptoms and health functioning. The relationship between somatic symptoms and traumatic stress symptoms was strongly affected by sleep, and the relationship between health functioning and traumatic stress symptoms was fully affected by sleep.20
An overview of treatment strategies
The first step in helping patients with PTSD-related sleep disturbances is to conduct a thorough medical and psychiatric history with a particular focus on sleep-wake function. The entire 24-hour period should be explored with respect to sleep-wake habits. Patients should be questioned about their views on what constitutes healthy sleep. A practical criterion for evaluating the severity of insomnia, for example, is to put greater weight on reports of daytime impairment as opposed to reports on the length of sleep duration.
Patients with PTSD may not accurately estimate their sleep times, so it is useful to focus on whether they feel restored during the day. Self-rating instruments such as the Insomnia Severity Index and the Pittsburgh Sleep Quality Index Addendum for PTSD are useful for measuring subjective sleep quality.21-23 A 2-week sleep-wake log is invaluable for obtaining a history of irregular sleep-wake patterns; napping; use of stimulants, hypnotics, or alcohol; diet; activity during the day; number of arousals; and perceived length of sleep time and its relationship to daytime mood and alertness. Patients should be asked about symptoms of morning headaches, cataplexy, hypnagogic or hypnopompic hallucinations, and sleep paralysis.
In addition, they should be questioned carefully about falling asleep while driving or while performing any other potentially dangerous activity. Additional history should be obtained from bed partners for events usually not perceived by the patients, such as snoring, respiratory pauses longer than 10 seconds, unusual body movements, or violent motor behavior. Concerns about sleep apnea, narcolepsy, or excessive sleep-related motor behavior should prompt a referral to a sleep laboratory for di-agnostic polysomnography. Sleep apnea, when present, should be aggressively treated given its potential for aggravating PTSD-related nightmares and insomnia.24
