Dealing with anxiety? Deep sleep may help, researchers say

More than 40 million adults in the United States deal with an anxiety disorder of some kind, which makes it the most common mental illness in the country, according to the Anxiety and Depression Association of America.

While anxiety disorders develop from a variety of risk factors — such as life events, genetics and personality — there are also a variety of treatment options that can help.

» RELATED: Getting more shut eye may help your heart health, study shows

According to new research, deep sleep may be among the most reliable and readily available treatments.

The study, published in Nature, found that not sleeping enough can lead to changes in the brain that are linked to higher levels of anxiety.

But, researchers note, it’s not just getting enough sleep that’s important, it also matters what kind of sleep you log.

High-quality, non-REM sleep — often called deep sleep — is the most effective at reducing anxiety levels the following day, researchers found. They also noted that a sleepless night can make you up to 30% more anxious the next day.

"Deep sleep had restored the brain's prefrontal mechanism that regulates our emotions, lowering emotional and physiological reactivity and preventing the escalation of anxiety," said Eti Ben Simon, the study's lead author.

The study initially looked at 18 participants. Researchers found that anxiety levels were significantly lower following a full night’s sleep, especially for people who logged more non-REM, slow-wave sleep.

They then looked to replicate the results with a larger group and through an online survey of 280 participants. Across the groups, the results confirmed that the participants who got more deep sleep were less likely to report symptoms of anxiety the next day.

"People with anxiety disorders routinely report having disturbed sleep, but rarely is sleep improvement considered as a clinical recommendation for lowering anxiety,” Simon said. "Our study not only establishes a causal connection between sleep and anxiety, but it identifies the kind of deep, non-REM sleep we need to calm the overanxious brain."