Excessive sleepiness not only affects your physical health, it has a big impact on your mental health as well. When you don't get the 7-9 hours of quality sleep you need, it can heavily influence your outlook on life, energy level, motivation, and emotions.
If you're feeling low, you may not realize that lack of sleep is the culprit. But even small levels of sleep deprivation over time can chip away at your happiness. You might see that you're less enthusiastic, more irritable, or even have some of the symptoms of clinical depression, such as feeling persistently sad or empty. All these alterations to your mood can affect not only your individual mental health, but your relationships and family dynamics as well.
The link between sleep and mood has been seen over and over by researchers and doctors. For example, people with insomnia have greater levels of depression and anxiety than those who sleep normally. They are 10 times as likely to have clinical depression and 17 times as likely to have clinical anxiety. The more a person experiences insomnia and the more frequently they wake at night as a result, the higher the chances of developing depression.
Obstructive sleep apnea, a condition in which a person wakes frequently and very briefly throughout the night, is linked to depression as well. In one study of nearly 19,000 people, those with obstructive sleep apnea were five times as likely to suffer from clinical depression. Researchers believe this is because when sleep is disrupted over and over, it can alter brain activity and neurochemicals that affect a person's mood and thinking.
The relationship between sleep and mood is complex, because disrupted sleep can lead to emotional changes, clinical depression or anxiety (as well as other psychiatric conditions), but these conditions can also compound or further disrupt sleep. In fact, altered sleep patterns are a hallmark of many mental health issues. If you find yourself sleeping too little or too much on a regular basis, it's important to bring this up with your doctor so the two of you can look at your total physical and mental health picture and decide if further tests or a treatment plan is necessary.