Sleep is a seductive but fickle beast. It never seems to arrive when you want it to (ahem—at nighttime), trying to suck you in during the daytime instead. But a night without sleep could raise your anxiety levels up to 30%, according to a new study.
The research, published in the journal Nature Human Behaviour, shows that deep sleep—aka non-rapid eye movement (NREM) slow-wave sleep—is the most important for calming an emotionally stressed mind. This type of sleep typically comes later in the night and is characterized by lowered heart rates and blood pressure, slowed breathing, and stillness in the body. And it’s a two-way street: The study found that a sleepless night ups anxiety levels the next day, and deep sleep helps reduce stress.
"We have identified a new function of deep sleep, one that decreases anxiety overnight by reorganizing connections in the brain," said study senior author Matthew Walker, Ph.D., a University of California, Berkeley professor of neuroscience and psychology and director and founder of the Center for Human Sleep Science. "Deep sleep seems to be a natural anxiolytic (anxiety inhibitor), so long as we get it each and every night."
Anxiety disorders affect 40 million American adults and are on the rise in kids and teens, says the Anxiety and Depression Association of America. And this promising research from UC Berkeley, which monitored brain activity and anxiety levels in 48 adult participants during both sleepless nights and nights with deep sleep, points to sleep as a natural, drug-free way to help relieve symptoms of anxiety disorders.
The researchers found that the medial prefrontal cortex—a part of the brain that helps limit anxiety—shuts down after a sleepless night, and the emotional centers of the brain go into overdrive. Conversely, the participants’ anxiety dropped significantly after a full night of sleep, especially if they had higher levels of NREM sleep.
"Without sleep, it's almost as if the brain is too heavy on the emotional accelerator pedal, without enough brake," explained Dr. Walker in a news release.
How to Get More Deep Sleep
Even small changes in your sleep quality during the night can affect your levels of emotional stress and anxiety during the next day, according to the study. So how do you improve that sleep quality?
The first thing to assess is your sleep hygiene. That means adopting the following good habits to boost your chances of solid shut-eye, according to the National Sleep Foundation:
- Optimize your bedroom environment. Make sure your room is on the cooler side (between 60 and 70 degrees), remove bright light sources, and consider white noise machines or blackout curtains. And don’t forget comfy pillows and a mattress you love.
- Stick to a schedule. Getting your body used to a nighttime routine will help prep your body for a better night’s sleep. For example, that may mean taking a warm shower, reading a book, or drinking some (non-caffeinated!) tea before bed. Try to stick to similar sleep and waking times every day.
- Limit your naps. Naps can be great, sure, but if you regularly nap for more than 20-30 minutes, it can disrupt your nighttime sleep even more.
- Avoid certain foods and drinks before bed. While that nightcap may help you fall asleep quickly, it will harm your sleep quality and make it less likely that you’ll wake up feeling rested. Avoid caffeine within the hours before bedtime as well. Certain foods can also cause issue—try to avoid fatty or fried foods, spicy meals, carbonated drinks, and citrus fruits before bed.
- Keep your bedroom a tech-free zone. Ban your smart phones, tablets, and laptops from the bedroom! The blue light from these devices can disrupt your sleep—and having these devices by your bedside can make it tempting to scroll through your social media feeds into the night. Swap out your phone’s alarm app for an old-fashioned alarm clock instead.
To try to get more deep sleep, specifically, the American Sleep Association (ASA) suggests making sure you’re giving yourself enough sleep time overall. That’s because deep sleep typically comes later in the sleep cycle, so if you cut down the number of hours you’re asleep, it majorly cuts into your deep sleep time, too.
Additionally, some experts say vigorous exercise can help boost your amount of deep sleep, says the ASA. Try adopting an aerobic exercise routine if you’re finding yourself awake all night. Running, swimming, or jogging can be great options—just remember not to schedule your workouts before bedtime, which could make it harder to fall asleep.
And if you’re still struggling to sleep or suspect you have a sleep disorder like insomnia, don’t be afraid to seek help from the pros. Your primary care doctor is an excellent place to start, and they may also refer you to a specialist. Some cognitive behavioral therapists also specialize in treating people with sleep problems like insomnia, according to the Mayo Clinic.