If you’re suffering from depression, there’s good news: there could be a very simple fix for you.

Depression can be absolutely debilitating for its sufferers, leading to fatigue and a general lack of will to do anything, a self-perpetuating cycle that only seems to get worse and worse. But for some people, there may be a very simple reason behind it: you’re not getting enough sleep because of sleep apnea, according to a new study.

Researchers found that patients who suffered from both depression and sleep apnea were treated with a continuous positive airway pressure system, or CPAP, according to a UPI report.

It could be a groundbreaking new finding that could pave the way toward primary care physicians active depressive patients about thei rsleep and possibly recommending getting testing for sleep apnea in addition to being prescribed antidepressants.

The study, which was published in the Journal of Clinical Sleep Medicine, found that effective treatment of obstructive sleep apnea resulted in a big improvement in the symptoms of depression, and that included suicidal ideation, Dr. David R. Hillman, a clinical professor at the University of Western Australia, said in a press release as reported by UPI.

Hillman called sleep apnea a “notoriously undiagnosed condition,” and that many times depression may simply be misdiagnosed sleep apnea, an exciting finding as depression can be very difficult to treat, but there are many established methods to treat sleep apnea.

The study involved 426 participants — 183 women and 243 men at an average age of 52 — who were being referred to a hospital sleep center to be checked for sleep apnea. They were also assessed for depressive symptoms via a questionnaire.

A total of 293 of the patients were diagnosed with sleep apnea and prescribed a CPAP machine, which is a mask that uses mild air pressure to keep airways open during sleep. These patients used the CPAP for at least five hours per night over a period of three months.

After the treatment was over with, only 4 percent of the patients described still being depressed even after the treatment, and of the 41 patients who had reported suicidal ideation, not even one of them felt the same way when the three month period came to an end.

Obstructive sleep apnea is a sleep disorder that typically features pauses in breathing, or at least infrequent breathing during sleep due to a constriction of the airway. Snoring is often a hallmark of apnea, although it is not necessarily indicative that apnea is occurring, which is much more serious and involved an actual pause in breathing during sleep that can last several seconds to several minutes. By definition, it happens at least five times per hour.

Oftentimes, people who have sleep apnea don’t even realize it, unless they have a partner who sees that the person has stopped breathing and then resumes seconds or even minutes later. This disrupts the quality of the person’s sleep, leading to tiredness and fatigue during periods where they are awake, and in serious cases it can create a risk of sudden death.

As a result, it stands to reason why sleep apnea could be behind depression symptoms, as it can lead to a person feeling fatigued and unwell throughout the day every single day, rather than refreshed.

When breathing pauses, carbon dioxide builds up in the blood stream, and chemoreceptors in the blood stream noticed these high CO2 levels causing the brain to wake the person up and take a breath — an interruption in sleep that prevents prolonged period of deep sleep necessary to the human body.

Sleep apnea takes three forms: central, obstructive, and a combination of the two. Obstructive is by far the most common at 84 percent, where as central — which is when a lack of respiratory effort is to blame — accounts for just 0.4 percent of cases. In obstruct sleep apnea, there is a physical block to the airflow despite adequate respiratory effort, and snoring is common in people who have this. The National Institutes of Health estimates that about 12 million Americans have OSA, and that there may be many more but people don’t realize they have it or figure it is normal and don’t report it.

Sleep apnea is often so hard to diagnose because people don’t realize they have difficulty breathing even when they awaken, simply falling back to sleep and thinking nothing of it. Usually, it is recognized by a partner witnessing episodes of sleep apnea, so symptoms can be present for many years without being identified. This can be especially a problem for single people who have grown accustomed to the fatigue and assume it’s normal, and do not have someone who sleeps next to them an can identify these symptoms.