Millions of people across the nation are suffering from depression — but they may not realize just how easily they could cure it immediately.

That’s because an important new study has found that sleep apnea may be the root cause for many cases of depression, which can be extremely debilitating and result in fatigue and a general lack of zeal for life, something that only seems to get worse for most people — which is why this study could be incredibly good news, as researchers have found that by treating them with a continuous positive airway pressure system (CPAP), many could be cured, according to a UPI report.

This huge new finding could lay the groundwork for primary care physicians looking into a person’s sleep habits as a possible reason for depression. It could be an additional treatment option to prescribing antidepressants, and would involve nothing more than a sleep study to determine just how well a person is sleeping.

The findings were published in the Journal of Clinical Sleep Medicine, and Dr. David R. Hillman, a clinical professor at the University of Western Australia, said the research has found that effective treatment of obstructive sleep apnea resulted in major positive impacts to symptoms of depression, sometimes in cases so severe they involve suicidal ideation, according to the report.

Sleep apnea is very often undiagnosed, and what the study shows is that depression may simply be a case of misdiagnosed sleep apnea. Since depression is so incredibly difficult to treat and sleep apnea is relatively easy to treat, this is an important finding that could help millions of Americans break out of a depression they may have been suffering from for many years.

The study involved 183 women and 243 men of an average age of 52 who were referred to a hospital sleep center to see if they had sleep apnea, and they were also checked for depression by filling out a questionnaire. The findings were intriguing: after diagnosing 293 of the patients with sleep apnea and giving them a CPAP machine, which uses mild air pressure to keep the airways clear during sleep, and using the machine for five hours per night at least for three months, only 4 percent of the patients were still depressed. About 41 patients had reported suicidal ideation before the test, and not one of them did after the three-month period — an exciting finding in deed.

Obstructive sleep apnea can wreak havoc on the human body. When a person falls into a deep sleep, the airways will constrict, oftentimes causing loud snoring. For those with severe apnea, it will feature pauses in breathing of seconds or even minutes at a time, by definition at least five times a night. When this happens, the brain interrupts sleep to resume breathing, and this will result in unsatisfactory sleep and feelings of fatigue and tiredness throughout the day, which beyond being draining can also lead to health problems later in life. In rare cases, sleep apnea can result in death during sleep.

Unfortunately, many people with sleep apnea don’t even realize they have it, especially single people who don’t have anyone who would notice them stop breathing or snore extremely loudly. People with apnea who awake in the middle of the night don’t realize why and think nothing of it, and although they feel fatigued during the day, they have come to think this is normal.

As this study seems to suggest, sleep apnea can result in people becoming depressed with a total lack of energy, feeling unwell throughout the day rather than refreshed after a good night’s sleep.

Sleep apnea takes on three forms, with obstructive sleep apnea being the most common at 84 percent of sufferers. There is also central sleep apnea, which is more rare and is a problem with the respiratory system, and the third form is a combination of the two. Most people have obstructive, when the airways are constricted. The National Institutes of Health estimates that 12 million Americans suffer from this form of sleep apnea, and perhaps many more who don’t realize they have it.