What is the link between depression and sleep ?

How depression affects sleep

Sleep problems are a major symptom of depression. As many as 90% of people with clinical depression will experience difficulties with their sleep. Depression has even been identified as the most common cause of long-term insomnia.²

But what is insomnia?

Insomnia is a common sleep problem where a person suffers from sleeplessness for a long time. Symptoms include lying awake for extended periods of time at night, being unable to sleep, waking up regularly throughout the night and not being able to get back to sleep once awake.³

As with many sleep problems, the symptoms of insomnia and depression are not just confined to the murky midnight hours. Daytime fatigue, sleepiness and low energy levels are all symptoms of both depression and insomnia.

This can be made worse by sleep problems being a common side effect of the use of antidepressants. So you find yourself with sleep problems as a result of both the condition and the treatment.

It is not just problems with getting to sleep that can be caused by depression. Some people with depression find they have completely the opposite problem, feeling excessively sleepy and struggling to stay awake during the day. This is called hypersomnia.⁴

Hypersomia is less common than insomnia in those with depression. However, it is seen more frequently in women and those under 30. Some sufferers of depression will even experience insomnia and hypersomnia in the same depressive episode.⁵

How sleep problems affect depression

People with insomnia are 10 times more likely to have clinical depression and 17 times as likely to have clinical anxiety.⁶

The quality of our sleep can affect our daytime mood, our emotional response and our ability to regulate our positive and negative emotions.⁷ This is because sleep has a big impact on how two parts of our brain, called the amygdala and hippocampus, work.

The amygdala has an important job in our emotional regulation, and how negatively or intensely we experience events.⁸ While the hippocampus is involved in how we process emotion and stress.⁹

A lack of sleep can negatively impact these two parts of our brain. Which makes us more likely to experience negative events more intensely, and reduce our ability to cope with stress. Over the long term this can make us more susceptible to developing mental health problems and mood disorders.¹⁰

The impact of this should not be underestimated. Problems with sleep are considered a warning sign on whether a person will develop depression, and can be seen as a vital early indicator of a depression relapse.¹¹

Studies have even suggested insomnia is linked to an elevated risk of suicide, in adults, teenagers and children.¹²

How to recognise depression and sleep problems

While depression and sleep problems are closely linked, it is important to note they are separate conditions. Therefore, a helpful place to start, when thinking about your mental health and sleep can be by recognising the different signs of the two conditions.

Treat sleep problems to improve depression

Improvements in sleep have been linked to helping treat depression, reducing the severity of depression and hastening recovery. There is some evidence to even suggest that getting good sleep and sticking to healthy sleep habits can be used as a preventative measure for depression.

In terms of how much sleep you need to manage your emotional wellbeing, there is no exact answer. The amount of sleep you need varies by age and from person to person. However, the National Sleep Foundation’s ‘sleep guidelines’, are a good starting point to help you find out if you are getting enough sleep.

When to talk to your Doctor

If you experience symptoms of depression for most of the day for more than 2 weeks then it is worth making an appointment to see your GP.

If you are experiencing insomnia, without depressive symptoms, you may want to try our practical sleep hygiene tips. You should see your GP about treatment options if changing sleeping habits have not helped you in falling asleep, or if you have had trouble sleeping for months and/or your insomnia is affecting your ability to cope.