The fact that insomnia may cause depression is perhaps unsurprising to many insomniacs, yet researchers are still split as to whether insomnia is a symptom or a cause of depression.
Sleep problems are usually seen as a symptom of depression - however it appears that newer research is finding that depression is often a symptom of insomnia.
A study in 2010 found that insomnia may cause clinical depression and more recently a presentation made by scientists at the American College of Neuropsychopharmacology annual meeting confirmed that sleep deprivation may cause depression.
Scientists found changes in the responses and actual brain structure of rats that were sleep deprived which mimicked the changes seen in the brains of depressed humans.
So how sleep deprived were the rats in this experiment before they started showing symptoms of depression? Well, scientists found that after a week of only four hours sleep, there was less sensitivity in the areas of the brain that regulate mood. After one month of reduced sleep there were changes in the hippocampus area of the brain - it had actually reduced in volume and was producing fewer new cells.
At both the one week and one month stages of sleep deprivation, scientists found that the brains of the rats had become less efficient at transmitting serotonin signals. It took a week of recovery sleep before serotonin receptors returned to their original levels.
We were surprised that there were such dramatic effects in such a short amount of time even though the rats were still getting four hours of sleep each day. It is worth reiterating that this study was performed on rats, not humans. However, it does show just how serious the consequences of sleep deprivation can be in a relatively short period of time.
Yet another reminder that insomnia should never be ignored.
Last updated: January 16, 2012