SILVER SPRING, Md. - Imagine you start the day with your phone charged to 80%. However, there won’t be any outlets to recharge until the end of the day. Phone calls, text messages, social media breaks — it adds up. Will 80% be enough to last the average work day?
That is essentially how people function with even mild sleep debt, which is something most of us suffer from. A third of US adults report that they usually get less than the recommended amount of sleep, according to the Centers for Disease and Prevention.
Sleep debt can be accumulated over days, weeks and years of inconsistent sleep patterns, so every time you don’t receive a full seven to eight hours of sleep per night, that loss is added to your existing sleep debt and can be severely impairing.
Consequences of sleep debt include impeding our ability to regulate stress, emotions and cognition. Researchers from the Center for Military Psychiatry and Neuroscience (CMPN) at the Walter Reed Army Institute of Research are responsible for investigating the relationship between sleep and how it optimizes human performance. Their efforts provide information to leaders who can better prepare their Soldiers for missions and their post-Army futures.
“It is important to understand that when you are sleep deprived, you don’t perform as well,” said Dr. Janna Mantua, CMPN Operational Research Team, lead scientist.
There are two major types of sleep that your body cycles through to get a good night’s rest: non-rapid eye movement sleep and rapid eye movement, or REM, sleep. While non-REM sleep is essential for hormone regulation and protein synthesis during muscle recovery, REM sleep is important for emotional processing and boosting good mental health.
Rapid eye movement sleep comes at the end of the night, so it is the sleep stage that is most likely to be missed if one isn’t getting enough sleep.
“If you are not getting enough REM sleep, it is possible that you will have more emotional disturbances whether or not you have preexisting psychological distress in the form of anxiety or depression,” Mantua said. “Those emotional disturbances can be in the form of increased stress, burnout or poorer mood.”
As the night goes on, the proportion of your sleep cycle that is REM gets longer and longer, which is why you tend to wake up remembering the final dream of the sleep period. Mantua said that each sleep cycle doesn’t stand alone, and all of them are required in order to get a good night’s sleep.
“If you have good quality sleep and are getting enough hours of sleep then you are getting all the sleep stages you need,” Mantua said.
The benefits of getting good sleep can go beyond daily performance and can, in some cases, prevent long-term problems. This is because everything you experience is predominantly filed away into your long-term memory during sleep, and when your brain does this filing, it is also assigning the proper emotional response to each memory. Sleeping helps regulate this emotional labeling. For Soldiers who experience something traumatic, sleep will help them process events and reduce the chances of serious long-term emotional dysregulation, such as post-traumatic stress disorder.
“If you were to be sleep deprived and experience something very emotional, the emotionality of it stays really high,” Mantua said. “But if you sleep, you save the memory and the emotionality is slightly reduced.”
The frontal lobe regulates emotions and processes events and it does not function as effectively during periods of sleep deprivation. This means during stressful events, sleep-deprived individuals may perceive something as overly negative and respond disproportionally to the event.
“Our ability to translate what is a threat and not a threat and respond appropriately is critical, especially when you are working with the same team all the time, making decisions and regulating the perception of a threat,” said Lt. Col. Vincent Capaldi, CMPN senior medical scientist.
There are experiences that will remain traumatic memories, however. Taking the extra time to sleep and recover over several nights following a traumatic event will help to file your memories away in the proper place with the proper amount of emotional response from your brain, minimizing some effects of acute stress disorder and PTSD.
“[Sleep debt] doesn’t necessarily create the pathologic conditions but it can certainly make the pathological conditions worse, but if we get enough quality and quantity of sleep then we will mitigate a lot of the symptoms that are associated with these conditions,” said Lt. Col. Scott Williams, CMPN director.
This article is the first of a series that explores the relationship between sleep and mental health and how this correlation affects Soldier and unit readiness.