The neural link between depression and sleep problems has been identified for the first time in a new study by researchers. They found functional connectivity between the areas of the brain associated with short-term memory, self, and negative emotions - causing sufferers to dwell on bad thoughts and leading to a poor quality of sleep.

Analysing data from around 10,000 people, the researchers examined the neural mechanisms underlying the relation between depression and quality of sleep.

In the brains of those living with depressive problems, they discovered a strong connection between the dorsolateral prefrontal cortex (associated with short-term memory), the precuneus (associated with the self) and the lateral orbitofrontal cortex (associated with negative emotion). A total of 162 functional connectivity links involving these areas were identified. Of these links, 39 were also associated with the Depressive Problems scores.

The brain areas with increased functional connectivity associated with both sleep and Depressive Problems scores included the lateral orbitofrontal cortex, dorsolateral prefrontal cortex, anterior and posterior cingulate cortices, insula, parahippocampal gyrus, hippocampus, amygdala, temporal cortex, and precuneus.

The analysis showed that these functional connectivities underlie the relation between depressive problems and sleep quality.

The researchers conclude that increased functional connectivity between these brain regions provides a neural basis for how depression is related to poor sleep quality.

Depression and sleep problems often go hand-in-hand. About 75% of depressed patients report significant levels of sleep disturbance, such as difficulty of falling asleep and short duration of sleep (insomnia). People with insomnia also have a higher risk of developing depression and anxiety than those who sleep normally.

https://warwick.ac.uk/newsandevents/pressreleases/neural_link_between

https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2688429