Sleep apnea increases the risk of depression

Sleep apnea syndrome (SAS), which consists of involuntary pauses in breathing during sleep, often has side effects. The number of these respiratory interruptions varies from patient to patient. In the most severe cases, a person may stop breathing up to 30 times per hour repeatedly during the night. During these apneic attacks, the oxygen level in the blood decreases significantly. This drop in oxygenation causes high blood pressure and an accelerated heart rate.

Also, repeatedly, these disorders can lead to cardiovascular disease, CVA or even diabetes. But to the surprise of many researchers, recent work shows that sleep apnea does not only cause physiological pathologies. An American team has studied the link between sleep apnea and depression. Their results indicate that SAS is a factor that increases the risks of depression.

Depression, a disease of the century

Depression is one of the diseases of our century. In recent years, the number of cases of depression has been steadily increasing. This mental disorder is manifested by fatigue, a feeling of great sadness, despair and anxiety. In the most severe cases, depression can lead to suicide.

In the therapeutic setting, the treatment generally consists of a prescription of antidepressants. But in many cases (nearly 50%), antidepressants do not improve the patient's condition. Several hypotheses have been put forward to explain this phenomenon. Disorders related to the thyroid, taking several drugs in parallel such as corticosteroids are often the causes of the lack of effect of antidepressants.

But the lack of improvement of the depressive state in patients not following any other drug treatment and suffering from no other pathology remained to be elucidated? Why do antidepressants have no effect in these individuals? Recent work provides new answers to these questions. According to these studies, sleep apnea and sleep disorders in general can cause depression. In addition, SAS alone is likely to block the beneficial effects of antidepressants.

The effects of sleep apnea on depression

Sleep apnea affects the quality of sleep. A feeling of great fatigue and daytime sleepiness are often the main symptoms. Fatigue has long been known to be a risk factor for depression. People treated for their insomnia see their depression improve.

But the researchers were surprised to find that polysomnography tests revealed the presence of sleep apnea in individuals suffering from severe depression who did not respond to antidepressants > and showing no symptoms of drowsiness. During the study, the latter were treated for their apnea by continuous positive pressure. Some of them showed a marked improvement in their depressive state after a few weeks.

This work highlights the importance of understanding sleep patterns in people with depression. Systematic screening for sleep apnea should be an integral part of the therapeutic follow-up of depression.

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