Obstructive sleep apnea (OSA) occurs when the throat muscles become so loose at rest during sleep that breathing stops. This happens several times at night and disrupts sleep. There is also a lack of oxygen. Its symptoms are loud snoring, sudden awakening at night, headache in the morning, dry mouth, sleepiness during the day.

In Canadian research, 30,000 people aged 45 to 85 years were studied. People who had a higher risk of OSA were found to be 40 percent more likely to have poor mental health. Over time, even among people who were initially well, the risk of developing mental health problems increased by 20 percent. Mainly depression, anxiety and stress increase.