Why Does A Lack Of Sleep Lead To Depression?


Generally speaking, the consensus has always been that insomnia is a result of other disorders such as depression, but now opinion may be changing.

Research from sleep expert Alice Gregory is now suggesting that that the link could also be working the other way, with those who suffer from insomnia more likely to develop depression and anxiety earlier in life.

Evidence over the last ten years has shown that disturbed sleep often comes before episodes of depression, and not afterwards.

When you think about it, it makes lots of sense, as we all feel pretty awful following a poor night’s sleep.


How is sleep linked to your mood?

Studies on the link between lack of sleep and depression have generally focused on a particular part of the brain called the amygdala.

The amygdala is small almond-shaped structure deep within the brain which is believed to be crucial to regulating our emotions and anxiety levels.

Studies showed that those who had been sleep deprived for around 35 hours had a greater amygdala response when they were presented with emotionally negative pictures compared to those who had not been sleep deprived.

Links with parts of the brain which regulate the amygdala seemed weaker too, meaning participants were perhaps less able to control their emotions.

While other factors definitely play into depression other than just a lack of sleep, it certainly does play a role.



Can insomnia and depression be inherited?

Professor Gregory’s research has also shown that the symptoms of sleep and insomnia could to some extent be part of the same genetic cluster.

This means that we could be inheriting genes which make us more susceptible to insomnia, and therefore depression too.

Her work has also looked at the relationship between the immune system and insomnia, finding that those suffering from depression may show higher levels of inflammation in their bodies.

This is because their immune systems appear to be in hyper-drive as they’re fighting infection or healing from injury.



What can be done about it?

There have been multiple studies recently which have suggested that improving our sleep could be the way to go about treating or preventing depression.

For example, researchers from Oxford University evaluated whether insomnia treatment also helped reduce symptoms of depression and anxiety.

They asked their participants to take steps such as setting a consistent wake up time and getting out of bed when they couldn’t sleep.

They found that those who underwent this treatment experienced reduced symptoms of both anxiety and depression.

There are now studies going on which are looking at whether improving our sleep could also help reduce other psychiatric difficulties, but if there’s one thing that the evidence definitely points towards, it’s that we need to start prioritising our sleep!

You can read the full extent of Professor Gregory’s thoughts on the link between sleep and depression at the Daily Mail, and check out all of our sleep-related post at our Sleepy People blog.