Can Sleep Apnea Increase Your Risk of Depression? | Ueno Snoring Clinic

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Ueno Snoring Clinic was featured on Fuji TV’s “Live News It!”

Watch our discussion of sleep disorders, snoring, and sleep apnea diagnosis at Ueno Snoring Clinic

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Ueno Snoring Clinic was featured in an article on Nippon TV’s “news every.”

Please use this as a starting point for thinking about testing or treatment for snoring, sleep apnea, and sleep disorders.

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Reviewed by Our Director

Kazuyuki Sugaya

Director / Anesthesiologist, Ueno Snoring Clinic

With more than 20,000 general anesthesia cases, our director provides care centered on the diagnosis and treatment of snoring and sleep apnea, tailored to each patient. [Insurance-Covered] Ueno Snoring Clinic

This article has been medically reviewed by Director Kazuyuki Sugaya and explains accurate medical information about testing and treatment for snoring and sleep apnea syndrome (SAS) in plain language.

This topic is also covered in detail in our director’s book, “Curing Snoring with the Latest Treatments” (Amazon Japan Best Seller: #1 in General Medicine, #1 in Clinical Internal Medicine, #2 in Home Medical & Health)

New Book by Our Director

“Curing Snoring with the Latest Treatments”

Written by an anesthesiologist who has overseen the sleep of more than 10,000 patients, this book is a modern guide to the latest snoring treatments.

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What deserves particular attention is that sleep apnea syndrome causes oxygen levels to drop repeatedly during sleep, and this can affect the brain, the autonomic nervous system, and mental health.
Snoring isn’t simply a matter of noise. It may be a sign that breathing is stopping during sleep and the body is becoming low on oxygen. And when this happens night after night, the effects can spread to the brain, heart, blood vessels, metabolism, and mental health.

Prompted by this recent news coverage, this article offers a clear, expert explanation of the relationship between sleep apnea syndrome and depression, low oxygen, daytime sleepiness, morning headaches, and the signs that warrant a medical evaluation.

What Is Sleep Apnea Syndrome?

Sleep apnea syndrome is a condition in which breathing repeatedly stops or becomes shallow during sleep. The most common type is obstructive sleep apnea, in which the airway in the throat narrows.
When we fall asleep, muscles throughout the body relax — this is entirely natural, but because the muscles around the throat relax too, the base of the tongue and the soft palate can sink downward more easily. As a result, the airway narrows, and when air struggles to pass through, snoring occurs. If the airway becomes fully blocked, breathing stops altogether.
In other words, snoring is the sound of a narrowing airway. It’s often a warning sign that comes just before breathing stops completely, and certain patterns deserve particular attention: loud snoring, breathing that pauses mid-sleep, and a sharp gasp for air afterward.

Why Low Oxygen Is the Real Concern

What makes sleep apnea syndrome concerning isn’t simply that sleep becomes lighter — the bigger issue is that blood oxygen levels drop each time breathing stops.
The human body runs on oxygen. The brain, heart, blood vessels, and muscles all depend on a steady oxygen supply to function. But when breathing repeatedly stops during sleep, the body becomes low on oxygen again and again.
When oxygen drops, the body senses danger and activates the sympathetic nervous system. In simple terms, even though you’re supposed to be asleep, your body is repeatedly going into “emergency mode.”
As a result, blood pressure tends to rise, the heart comes under added strain, and the blood vessels experience added stress. For some people whose blood pressure doesn’t drop at night, who have high blood pressure in the early morning, or whose blood pressure remains difficult to control even on medication, sleep apnea syndrome may be an underlying cause.

The Relationship Between Depression Risk and Sleep Apnea Syndrome

One point that drew particular attention in the recent news coverage was the relationship between sleep apnea syndrome and depression risk.
Sleep apnea syndrome and depression may seem like entirely separate conditions at first glance, but in practice, their symptoms overlap considerably.
For example, sleep apnea syndrome can produce symptoms such as the following:

These symptoms are easily mistaken for depression, adjustment disorder, or chronic fatigue. Of course, this isn’t to say that having sleep apnea syndrome automatically leads to depression. But it’s entirely plausible that the combination of nighttime low oxygen, fragmented sleep, chronic fatigue, and autonomic nervous system disruption makes a person more susceptible to mental health effects.
One thing worth being especially cautious about is the case where someone is being treated for depression, but underlying sleep apnea has been overlooked. Behind a low mood or poor concentration may be nightly episodes of apnea that have gone unnoticed.

When “Sleeping but Not Recovering” Wears Down the Mind

Sleep does more than simply rest the body. It plays a role in recovering the brain from fatigue, consolidating memories, regulating the autonomic nervous system, releasing hormones, and adjusting immune function.
But with sleep apnea syndrome, breathing stops repeatedly during sleep, and each time, the brain briefly rouses to a lighter stage of sleep. The person often has no conscious awareness of waking up, but these micro-arousals can be seen repeating on an EEG.
As a result, even someone who sleeps 7 or 8 hours may not actually be getting deep, restorative sleep.
When this state of “sleeping but not recovering” continues over time, daytime performance gradually declines. At first, it might just be feeling a little sleepy or having trouble concentrating. But as it becomes chronic, it can lead to real problems in daily life — more mistakes at work, feeling drowsy while driving, zoning out during meetings, spending entire days off asleep, or talking less with family.
When this continues, some people begin to feel as though they’re being lazy, or that they’ve become someone without any motivation.
In reality, though, this often isn’t a matter of willpower at all — it may reflect the fact that oxygen has been dropping during sleep, leaving the brain and body unable to truly recover.

Three Warning Signs You Shouldn’t Ignore

Three signs in particular are worth watching for as possible indicators of sleep apnea syndrome.

1. Strong Daytime Sleepiness

You feel sleepy during the day even though you’ve supposedly gotten enough sleep — strong drowsiness during meetings, while driving, after meals, or while working at a computer. This can be a sign that your sleep quality has declined.
Sleepiness while driving is especially dangerous. With sleep apnea syndrome, even if someone believes they’re “just a little sleepy,” their concentration and reaction time may actually be significantly reduced.

2. Not Waking Up Feeling Refreshed

Your body feels heavy from the moment you wake up, even though you’re sure you got a full night’s sleep. You keep hitting snooze. You’re exhausted the instant you open your eyes. This, too, is a symptom commonly seen with sleep apnea syndrome.
It’s not the number of hours that matters, but the quality of sleep. If breathing keeps stopping and the brain keeps rousing throughout the night, you won’t feel restored no matter how many hours you spend in bed.

3. Headaches Upon Waking

Morning headaches are another important sign. When blood oxygen levels drop during sleep, or carbon dioxide builds up, it can result in a headache upon waking.

Not Everyone Who Snores Has Severe Apnea — But Ignoring It Is Risky

Of course, not everyone who snores has severe sleep apnea syndrome. Snoring can also temporarily worsen due to fatigue, alcohol, nasal congestion, sleeping on your back, or weight gain.
That said, in the following situations, it’s best not to simply dismiss it as ordinary snoring:

Feedback from family members or a partner is especially important. Because sleep apnea syndrome happens while a person is asleep, it’s a condition that’s genuinely difficult to notice in yourself. More often than not, it’s the person sleeping next to you who notices something is wrong first.

Testing Looks at More Than “How Many Times Breathing Stopped” — It Also Measures How Far Oxygen Dropped

Testing for sleep apnea syndrome commonly uses a metric called AHI or REI — a number representing how many apnea and hypopnea events occur per hour.
In actual clinical practice, though, the number of events isn’t the only thing that matters. How far oxygen saturation drops, the severity of snoring, changes in pulse, sleeping position, daytime symptoms, and any related conditions are all important as well.
For example, even a moderate number of apnea events can place significant strain on the body if oxygen levels drop sharply. Conversely, someone whose numbers look mild on paper may still experience a major impact on daily life if their daytime sleepiness or difficulty concentrating is severe.

Treatment Isn’t Limited to CPAP — But CPAP Remains Important for Severe Cases

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There are several treatment options for sleep apnea syndrome.
For mild cases, or types that worsen depending on sleeping position, weight loss, limiting alcohol, sleeping on your side, treating nasal congestion, and other lifestyle changes can be effective.
For moderate-to-severe cases — particularly when oxygen drops significantly or daytime symptoms are pronounced — CPAP therapy becomes the primary treatment. CPAP delivers air through the nose during sleep to keep the throat’s airway from collapsing.
On the other hand, for people who don’t tolerate CPAP well, those with mild-to-moderate cases, those whose main symptom is snoring, or those with significant looseness in the throat tissue, a combination of approaches — such as an oral appliance, positional therapy, nasal treatment, or laser treatment — may be considered instead.
What matters most is that snoring doesn’t call for the same treatment in every case. Treatment should be chosen only after identifying whether the cause lies in the nose, the tongue, the throat, body weight, or jaw structure, and after determining the severity of the sleep apnea.

The More Mental Health Symptoms You Have, the More Important It Is Not to Overlook Sleep Apnea

When low mood, anxiety, irritability, poor concentration, and low motivation persist, most people assume it’s purely a mental health issue. And in many cases, treatment for psychological stress or depression itself is genuinely needed.
But it’s worth checking one more thing at the same time: your breathing during sleep.
The chronic decline in sleep quality caused by sleep apnea syndrome can produce symptoms that closely resemble a mental health condition. This is especially true if you’re tired from the moment you wake up, sleepy during the day, have been told by family that you snore or stop breathing, have gained weight, or have high blood pressure — in these cases, it’s worth getting checked for sleep apnea syndrome.

When to See a Doctor

If even one of the following applies to you, consider getting tested for sleep apnea syndrome.

Sleep apnea syndrome can often be evaluated with a simplified test you can do at home — sensors are attached to a finger and near the nose while you sleep as usual, allowing your breathing and any drop in oxygen level to be recorded. A more detailed PSG test can be arranged afterward if needed.
Some people hesitate, wondering whether snoring alone is a good enough reason to see a doctor. But snoring is a sign of an airway problem during sleep. Before letting it go unaddressed, it’s worth taking the time to check your condition.

Frequently Asked Questions

Summary: Not “Just Snoring” — It May Be a Warning From Your Body and Mind

Snoring isn’t simply noise. It may be a sign that the airway is narrowing during sleep and the body is struggling.
Left untreated, sleep apnea syndrome causes low oxygen, fragmented sleep, and an overactive sympathetic nervous system to repeat night after night. This can raise the risk of high blood pressure, heart attack, stroke, and diabetes, and may also be linked to low mood, poor concentration, and depressive symptoms.
In particular, strong daytime sleepiness, not waking up feeling refreshed, and morning headaches are signs that shouldn’t be overlooked.

Ueno Snoring Clinic provides care for snoring and sleep apnea syndrome tailored to each patient’s symptoms and test results — including insurance-covered testing and CPAP management, as well as self-pay snoring treatment.
Rather than dismissing snoring as something embarrassing, or writing it off as simply age or fatigue, we encourage you to see it as an opportunity to protect both your body and your mind, and to reach out for a consultation.