Chicken or the Egg: Depression or Sleep Apnea?

In the wake of Robin Williams’ untimely death by suicide, I think it’s appropriate to talk about the pink elephant in the room that no one seems to notice. Mr. Williams was known to suffer from severe depression, and there are reports that he also had early stages of Parkinson’s Disease. He also battled alcohol addiction. 

It’s estimated that about 20 million people suffer from depression. It’s a consensus that depression is caused by a multitude of various factors, with a number of different brain biochemical and structural abnormalities. 

Here are 7 known facts about depression, insomnia and obstructive sleep apnea:

1. We know that depression and insomnia and other sleep problems tend to go hand in hand. People with insomnia are found to have a ten-fold increased risk of developing depression later in life.(1) Treating insomnia in patients with depression resulting in almost double the rate of depression remission.(2) Another study found that the presence of depression and insomnia predicted a higher rate of obstructive sleep apnea.(3)

2. The hippocampus is one area in the brain (amongst many other areas) that is found to be smaller in people with depression.(4) This area controls long-term memory and recollection. Interestingly, this is the same area that is also found to be significantly diminished in patients with severe obstructive sleep apnea. 

3. Men and women who reported stopping breathing during sleep more than five times per week were 3 times more likely to show signs of major depression. Numerous studies show a strong bi-directional link between obstructive sleep apnea and depression.

4. Patients with severe insomnia who don’t respond to prescription sleep aids have about a 75% chance of having undiagnosed obstructive sleep apnea.(5)

5. In people with obstructive sleep apnea and depression, CPAP resulted in significant improvements in depression scores.(6)

6. Obstructive sleep apnea is known to significantly raise your risk of heart disease. (Mr. Williams underwent open heart surgery in 2009).

7. Many people with obstructive sleep apnea compensate for fatigue by intense physical exercise. (Mr. Williams was an avid cyclist).

There’s now lots more research on the ravaging effects of obstructive sleep apnea and oxygen deprivation on various areas of the brain, including the pre-frontal cortex, hippocampus, and the thalamus. Not only is the brain deprived of vital blood flow and oxygen, but brain tissue density and volume are also found to be smaller. One small shining light amongst all the bad news is that the hippocampus can regenerate to some degree with improved cognitive abilities after many months of CPAP use.(7)

Granted, you could argue that depression can lead to obstructive sleep apnea, since lower levels of activity can lead to weight gain. But then poor sleep quality can lead to low energy levels and lack of motivation to do anything, Poor sleep is also known to cause weight gain. Certain antidepressant medications are also known to cause significant weight gain, which can also aggravate this vicious cycle.

In addition, many people with insomnia or obstructive sleep apnea use alcohol as a sedative to fall asleep at night. However, because alcohol relaxes your throat’s muscles, more apneas can occur.

In my practice, whenever I see anyone with clinically significant depression requiring medication, in the vast majority of cases, the upper airway is very narrow. Typically, they can’t sleep on their backs, and one or both parents snore heavily. They are never able to wake up refreshed.

All this is speculation, since no one has examined Mr. Williams for obstructive sleep apnea. But statistically speaking, given all of the above, and boing in his age group, he has a relatively high chance of having had untreated obstructive sleep apnea.

If you are diagnosed with depression and obstructive sleep apnea, which came first—depression or sleep apnea?



 1. Ong, Jason C., et al. “Frequency and predictors of obstructive sleep apnea among individuals with major depressive disorder and insomnia.” Journal of psychosomatic research 67.2 (2009): 135-141.

2. Manber R; Edinger JD; Gress JL; San Pedro-Salcedo MG; Kuo TF; Kalista T. Cognitive behavioral therapy for insomnia enhances depression outcome in patients with comorbid major depressive disorder and insomnia. SLEEP 2008;31(4):489-495.Taylor, Daniel J., et al. “Epidemiology of insomnia, depression, and anxiety.” SLEEP. 28.11 (2005): 1457.

3. Wheaton, Anne G., et al. “Sleep disordered breathing and depression among US adults: National Health and Nutrition Examination Survey, 2005-2008.”Sleep 35.4 (2012): 461.


5. Krakow, Barry, Victor A. Ulibarri, and Edward A. Romero. “Patients with treatment-resistant insomnia taking nightly prescription medications for sleep: a retrospective assessment of diagnostic and treatment variables.” Primary care companion to the Journal of clinical psychiatry 12.4 (2010).

6. Schwartz DJ; Karatinos G. For individuals with obstructive sleep apnea, institution of cpap therapy is associated with an amelioration of symptoms of depression which is sustained long term. J Clin Sleep Med 2007;3(6):631-635.

7. Canessa, Nicola, et al. “Obstructive sleep apnea: brain structural changes and neurocognitive function before and after treatment.” American journal of respiratory and critical care medicine 183.10 (2011): 1419-1426.

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5 thoughts on “Chicken or the Egg: Depression or Sleep Apnea?

  1. I think his facial features can prove he probably had sleep apnea. His mouth looks crowded inside when he speaks, like his tongue is too large for his mouth. My brother-in-law and niece and nephew have mouths like that and they have severe sleep apnea. Gov. Chris Christie also has the same kind of mouth, where I really notice how much the tongue fills up the mouth and I wonder how they can get enough oxygen.

  2. I googled photos of Robin Williams and he has a short distance between his nose and upper lip (short philtrum). That same facial feature runs in my brother-in-law’s family and most of them have sleep apnea. I googled photos of Gov. Christie and he appears to have a really small mouth but not a short philtrum. I really hope soon those with sleep apnea are educated, diagnosed and guided to treatment.

  3. JP I agree. you can definitely look at his face and presume he had OSA. the prominent feature seen even with his mouth closed is that his maxilla is markedly recessed. it creates his signature look.

    now, if we are going to look at celebrity deaths and posit what may have contributed, I think the most glaring example is Michael Jackson. he had so much surgery on his face and nose, that his nasal airway was certainly reduced. his severe insomnia that drove him to use propofol, was without question being caused by sleep disordered breathing. the doctor who mismanaged him is at fault, not just for failing to properly monitor him, but for failing to diagnose and treat his SDB. adding propofol to that mix when MJ didn’t have much of an airway, was a predictably lethal combination.

    Dr. Park thank you for this post. I am just waiting for society and the medical community to get on board with the idea that we must consider OSA in all cases of mental illness and behavioral problems.

  4. I enjoyed your post. I think that most people don’t take depression seriously. Also, most people don’t understand how lack of sleep can cause depression. I hope that more people learn about the body’s problems with sleep deprivation and find out if maybe sleep apnea is disturbing their sleep. Thanks for sharing.

  5. I’ve had sleep apnea for almost three years now and I admit I hope my days are short. I’m not worried about dying from this; its living with it that’s awful. I have zero doubt that if I could wake up refreshed and rested, I would be remarkably un-depressed. I use an apap, and while it works some, I still feel overwhelmingly tired everyday. I lost my job and have no insurance now. There’s just nothing in this life worth dragging myself through the day for.