About 6% of the US population will experience post-traumatic stress disorder (PTSD) at some point in their lives, with PTSD rates being twice as high for women than for men. The symptoms, which may not even appear until months or even years later, include reliving the triggering event via flashbacks, avoiding scenarios that carry reminders of the event, experiencing intrusive thoughts and other mental health issues, and having trouble sleeping.
For many, PTSD can trigger sleep disorders, primarily insomnia and nightmares. However, the disorder can also be exacerbated by sleep issues. Read on for an overview of how PTSD and sleep are interrelated and which treatments can be most effective.
What is PTSD, and who does it affect?
PTSD wasn’t widely adopted as a psychiatric diagnosis until 1980, building on observations first made decades earlier, after World War I. Research and the definition of PTSD continued to be expanded and refined following World War II and the Vietnam War, resulting in a broader awareness of both the types of events that can trigger the onset of PTSD and the range of physical and psychological symptoms that can result.
The types of traumatic events that can trigger PTSD extend far beyond combat and other war-related exposure to violence. Sexual or physical abuse or assault, automobile accidents, natural or man-made disasters, or the sudden death of a loved one can also result in PTSD. The event doesn’t even need to be experienced directly: Research shows that bearing witness to trauma, as in a wartime setting or when a child sees a parent being abused, can also result in PTSD.
Overall, women are significantly more likely to develop PTSD than men, with women having a 10 to 12% likelihood over the course of their lives (compared to 5 to 6% for men). For women, sexual abuse is a large contributing trigger: A 2017 study analyzing World Health Organization surveys in the United States and 23 other countries found that respondents who had been raped had the highest risk for developing PTSD, followed by those who reported physical abuse by a romantic partner. Additionally, the study found that prior exposure to trauma increased the likelihood of developing PTSD after a subsequent traumatic event.
It’s important to remember that most people (about 96%) who are exposed to a traumatic event don’t go on to develop PTSD. For those who do, however, symptoms usually start within a few months but may manifest years later, according to the National Center for PTSD.
How PTSD can affect sleep and vice versa
The relationship between PTSD and sleep is bidirectional: The disorder usually affects sleep, and poor sleep can in turn exacerbate symptoms.
When someone has greater PTSD symptoms during their waking hours, they’re more likely to have trouble sleeping that night; plus, when someone has a poor night’s sleep, they’re more likely to have more intense PTSD symptoms the next day. Poor sleep can also hinder the effectiveness of therapy aimed at addressing the trauma.
Moreover, sleep issues themselves are often a core element of PTSD. The diagnostic criteria for PTSD include two main sleep-related aspects, says Philip Gehrman, Ph.D., professor of clinical psychology at the University of Pennsylvania and clinical psychologist at the Penn Sleep Centers.
Insomnia
The first is insomnia, or trouble falling asleep and/or staying asleep. While the insomnia rate in the general population is about 10 to 15%, it can be as high as 90% for people with PTSD, he noted.
The second category, nightmares, is also substantially higher for people who have PTSD, with about 50 to 70% experiencing recurring nightmares.
Nightmares and PTSD
Usually, dreaming helps with processing information gathered during waking hours. This includes emotional processing, which helps weaken the emotional intensity of disturbing events. It also includes the associative (and often bizarre) nature of dreams, in which the brain pulls together seemingly unrelated memories as part of retaining and transforming them.
For those with PTSD, however, the nightly replay of what occurred is akin to reliving it rather than transforming it and lessening the emotional impact.
“The only case where we actually replay memories in our dreams is with PTSD,” says Robert Stickgold, Ph.D., professor of psychiatry at Harvard Medical School, director of the Center for Sleep and Cognition at Beth Israel Deaconess Medical Center in Boston, and co-author of “When Brains Dream.”
“Normally, sleep is where the brain weakens the strength of the emotion that’s activated,” he explains, but that’s not the case with PTSD. “We believe that part of what causes PTSD to develop is that the brain when it’s sleeping, is unable to process those traumatic memories the way it normally would.”
The fact that someone with PTSD may continue to have the same dream on repeat may reflect the brain’s continued attempt to process the event, Gehrman says. One theory is that the intensity of the nightmare causes someone to wake up, interfering with that process. “So the next night,” he says, “our brain tries again and fails. It keeps trying to regulate the emotional intensity, but the nightmare causes us to wake up, and that interferes with this process.”
Another theory is that recurring nightmares related to PTSD may stem from hyper-arousal. “People with PTSD tend to be constantly on guard, looking for signs of danger,” Gehrman says. While this can manifest as an exaggerated startle response during waking hours, it also has implications for sleep. Not only does the hyper-arousal contribute to insomnia, he says, “the theory is that it’s triggering the nightmares.”
Being in this hyper-aroused state can also affect the amount of time spent in deep sleep and in REM sleep, he notes.
Restless legs syndrome
People with PTSD are also more likely to have restless limbs, which can make it harder to fall asleep and can also affect sleep quality. For those who experience restless legs syndrome, the symptoms typically occur prior to sleep, says Gehrman, resulting in “an urge to move around to get rid of that sensation.” A similar condition that occurs after someone’s already asleep is periodic limb movement disorder (PLMD), which can cause them to wake up after they’ve already drifted off. “Part of it may just be a greater restlessness,” says Gehrman. “They’re not settling into as deep of a sleep as other people.”
Although rates for PLMD vary, they’re generally considered to be much higher in people with PTSD. Moreover, “people who have one of these [conditions] are more likely to have the other,” he says.
Obstructive sleep apnea
People with PTSD are more likely to have obstructive sleep apnea, although it’s not yet clear why. However, given that sleep apnea results in frequent awakenings (which worsens sleep), it can exacerbate PTSD symptoms. “Sleep apnea may be another factor that triggers nightmares,” Gehrman notes. In addition, the fragmented sleep caused by sleep apnea can cut into REM sleep, the stage most associated with dreaming, and therefore thought to be crucial for emotionally processing the events.
Treating PTSD-related sleep issues
Although some people will continue to have PTSD-related symptoms (including sleep disturbances) for many years, the 2017 study analyzing World Health Organization data found that 25 to 40% of people diagnosed with PTSD recover within one year. That said, certain types of trauma, such as war-related trauma, childhood physical abuse, rape, and sexual assault, took longer to recover from, the study found.
Therapies
To address PTSD-related insomnia, which affects the ability to fall asleep and the ability to stay asleep, cognitive behavioral therapy for insomnia (CBT-I) is considered the first-line treatment. This generally consists of six to eight sessions, Gehrman says, and is often “very effective for helping people fall asleep and stay asleep at night.” The treatment also helps address the dread many PTSD sufferers have of falling asleep due to their recurring nightmares.
For the nightmares themselves — a form of CBT-I known as Image Rehearsal Therapy (IRT) can often be effective. In fact, it’s the only treatment the American Academy of Sleep Medicine recommends for PTSD nightmares. IRT can produce results after three or four sessions, Gehrman says.
Also called nightmare rescripting, IRT is a way for people to “change the story of the nightmare, to make it less intense and less distressing,” he says. After writing out the script of the nightmare they’ve been having, patients write out a new script incorporating the changes. “Then, each night before they go to bed, they read through the dream script and kind of mentally rehearse it,” Gehrman explains. “For people who have a good response to it, it can really break the cycle of the nightmare.”
Research Gehrman has conducted shows that even in cases where the nightmares don’t go away, their intensity can be greatly reduced. “Instead of a nightmare where people would wake up sweating, with their heart racing, and couldn’t go back to sleep, now on average it was more like a bad dream,” he explains. Because people weren’t in as much distress, they were able to fall back asleep more easily.
Usually, IRT is combined with CBT-I, Gehrman says, given that people who have nightmares “almost universally also have insomnia.”
Medications
Medications are another option that can help. Prazosin, which reduces the level of noradrenaline (a stress hormone) in the brain, has been shown to be very effective in reducing the frequency of nightmares and improving sleep quality. However, in a more recent study of veterans with PTSD, the results were less clear-cut, Gehrman notes. “It seems to be like image rehearsal,” he said, “where it works really well for some people but not for others.”
For insomnia, medication is considered a “second line” treatment (with CBT-I being the preferred method). These include sleep medications such as zolpidem, as well as various sedating antidepressants, Gehrman says.
Given the interrelationship between sleep issues and PTSD, focusing on sleep as part of treatment is key.
“It becomes this kind of vicious cycle that people get stuck in,” says Gehrman. “After exposure to a trauma, people develop PTSD, and that’s disrupting their sleep. But then, because their sleep is disrupted, that makes it harder to recover from PTSD.”
