When Bedtime Becomes A Battlefield: PTSD, Sleep and A New Road To Recovery

How new research could finally pave the way from recurring nightmares to restorative sleep

By Jess Wight | August 13, 2026

"The nightmares were the hardest part because they were recurring. I didn’t sleep well – I’d sleep an hour and a half, two hours at a time…it was kicking my butt. I was working at the time and I was tired all the time going into work…”

US Army Veteran, Kevin Cottrell, discussing the devastating effects of PTSD for his sleep health

A good night’s sleep is a vital component for good physical and mental health, allowing us to recharge our bodies and clear our minds. But for someone living with post-traumatic stress disorder (PTSD) – who spend much of their waking life navigating hypervigilance, emotional exhaustion and chronic anxiety – sleep isn’t just important; it’s a desperate necessity. Yet for many, closing their eyes brings no relief, turning what should be a peaceful opportunity to reset into a distressing replay of recurring nightmares and physical panic. A groundbreaking study, however, offers a rare glimmer of hope, showing that targeted sleep interventions have the potential to finally break this cycle and provide trauma survivors with the true rest they have been denied.

Research has broadly converged on around seven hours of sleep as beneficial for adult health. A joint consensus statement from the American Academy of Sleep Medicine and Sleep Research Society, based on a review by 15 sleep experts, recommends at least seven hours per night, while more recent research continues to identify approximately seven hours as a duration associated with favorable health and cognitive outcomes. Indeed, a study published just last month examined associations between sleep and various health outcomes in over 70,000 adults over an average of 8 years, also concluding an average of around seven hours is optimal.

Matthew Walker, a British neuroscientist and sleep expert, has spent decades researching the mechanism of sleep, and details its foundational role in his award-winning book ‘Why We Sleep’: Simply put, “When sleep is abundant, minds flourish. When it is deficient, they don’t”.

Sleeping for less than the recommended amount has been associated not only with symptomatic indicators of poor health but with structural neurological changes. Investigating the effects of long-term sleep deprivation using weighted MRI, researchers in 2014 uncovered significant loss of grey matter volume in the thalamus, a structure which is essential to normal brain function, serving as a central hub that coordinates sensory processing, attention, consciousness, and sleep-wake regulation. More recently, a meta-analysis published last year further corroborates this finding, with authors concluding the thalamus is a region consistently altered by sleep deprivation.     

While sleep deprivation impacts the general population, the burden is exponentially higher for those living with trauma. Research into sleep among people with PTSD supports this lived experience: a comprehensive meta-analysis used years of polysomnography – overnight sleep-lab – data to measure brain activity during rest. These findings were stark; individuals with PTSD were found to spend significantly less time in deep, restorative slow-wave sleep, wake up far more frequently through the night, and suffer from overall lower sleep efficiency compared to healthy adults.

Sleep disturbances are highly prevalent among people with PTSD, with around 70–90% of patients reporting sleep problems. A 2021 systematic review and meta-analysis review found that approximately 70% report insomnia symptoms, while 50–70% experience recurrent distressing nightmares. The researchers found that the more severe a person’s PTSD symptoms are, the harder their brain struggles to complete a basic, restorative sleep cycle, suggesting that their nighttime difficulties are not simply subjective experiences but reflect measurable physiological disruption.

These findings raise an important question: if inadequate sleep is associated with structural changes in the brain, what might this look like in people for whom disrupted sleep is a persistent feature of PTSD? A 2015 neuroimaging study examined this relationship, finding that greater sleep disturbances were associated with reduced grey matter volume in the amygdala, hippocampus and anterior cingulate cortex among trauma-exposed individuals, with the pattern particularly evident in those with PTSD.

These regions are central to the processing of fear, memory and emotional regulation, suggesting that the structural changes associated with sleep disturbance may overlap with some of the brain systems already implicated in PTSD. While the study cannot establish that poor sleep caused these changes, it provides further evidence of a relationship between persistent sleep disruption and structural differences in the brain.

Another disruptive contributor to poor sleep is the presence of nightmares. For individuals with PTSD, these are not simply a common occurrence; they are embedded within the disorder's diagnostic criteria in the DSM-5 as a form of traumatic re-experiencing. Literature reviews indicate around 50–70% of people with PTSD report recurrent nightmares, making them one of the most prevalent symptoms of the disorder. By comparison, nightmare disorder affects roughly 5% of the general population.

These nightmares may directly replay aspects of a traumatic experience or take a more symbolic form, involving themes of threat, helplessness, or danger. Often accompanied by abrupt awakenings and heightened physiological arousal, recurrent nightmares can reinforce fear of going to bed and contribute to daytime distress and fatigue.

Researchers studying sleep disturbance in Vietnam combat-related PTSD patients reported greater vigilance even while asleep, suggesting that the brain may remain in a heightened state of threat detection rather than fully disengaging from its vigilance during sleep. More recently, a 2019 study used EEG brain imaging to uncover patterns consistent with both reduced sleep depth and increased cortical activation, further indicating the brain may remain more readily responsive to threat even during sleep. This could suggest that nightmares occur within a broader state of physiological hyperarousal rather than being isolated bad dreams.

Many individuals struggling with PTSD find themselves stuck in a self-perpetuating cycle: trauma disrupts sleep, disrupted sleep increases vulnerability to nightmares, and nightmares further disrupt sleep. According to Public Health Canada, 1 in 2 adults have trouble going to sleep or staying asleep. As a result, many people turn to sleep aids in an attempt to address these difficulties. One aid often reached for is cannabis: research shows around 16% of Canadian adults have used cannabis-derived products to help them sleep in the last year.

Cannabis use is disproportionately common among people with PTSD, and research consistently finds an association between PTSD symptoms and cannabis use or cannabis use disorder (CUD). A 2022 systematic review of 45 studies found that 82% reported a significant association between recreational cannabis use and PTSD. The evidence supported several possible explanations, including self-medication, where people use cannabis to reduce distressing PTSD symptoms, as well as the possibility that cannabis use itself may contribute to or maintain PTSD-related difficulties. It is important to note, however, that most of the existing studies are observational, thus the direction of causality remains uncertain.

The distinction between cannabis use and cannabis use disorder (CUD) is important. CUD refers to a pattern of cannabis use involving impaired control, continued use despite problems, craving, or other clinically significant consequences; it is more onerous regular daily cannabis use. In people with PTSD, more frequent cannabis use has been associated with greater psychiatric and functional difficulties. For example, a 2022 study of US veterans with PTSD or subthreshold PTSD found that veterans using cannabis more than weekly were more likely to report depression, anxiety, suicidal ideation, poorer cognitive functioning, and avoidance-based coping.

There is also an important question about whether cannabis actually improves PTSD symptoms. A 2024 systematic review found no convincing overall evidence that cannabis or cannabinoids improve PTSD, reporting that the studies involving people with comorbid PTSD and CUD tended to find risks of worsening symptoms. Consequently, the current Veteran Affairs and Department of Defense Clinical Practice Guideline recommends against using cannabis or cannabis derivatives as a treatment for PTSD.

Following years of publications in which cannabis use in PTSD has largely been discussed in terms of self-medication and potential harms, new research is beginning to suggest that specific cannabinoids – substances derived from cannabis - may have therapeutic potential for some PTSD symptoms.

A particularly important new study published last week investigated dronabinol, a synthetic form of THC, in adults with PTSD and recurrent nightmares. The trial involved people with PTSD taking either dronabinol or a placebo once daily before bedtime for 10 weeks. Strikingly, the individuals receiving dronabinol experienced a significantly greater reduction in the frequency and intensity of PTSD-related nightmares than those receiving placebo.

This research acts as a beacon of hope for people struggling with PTSD, since nightmares are not simply an unpleasant side effect, they can contribute to fragmented sleep, fear of sleep and persistent sleep disturbance. A treatment capable of directly reducing trauma-related nightmares could therefore have implications beyond the dreams themselves.

“The best bridge between despair and hope is a good night’s sleep.”

From Matthew Walker, Neuroscientist and sleep expert, in his book ‘Why We Sleep’

Beyond quieter nights, targeted treatments that silence recurring nightmares offer something far more transformative: the chance for the brain to truly heal. When sleep is restored, there is an opportunity for the cycle of hypervigilance, exhaustion, and emotional dysregulation to begin to ease. By moving away from unguided self-medication and towards precise, evidence-based therapies like dronabinol, we move closer to a reality where trauma survivors aren’t just surviving their nights, they are reclaiming their days. Rebuilding healthy sleep may well be the foundation upon which real, lasting healing from PTSD finally becomes possible.