Brain trauma may disrupt melatonin production, disturb sleep

Sleep is never the same after a devastating brain injury and researchers now have a clearer idea why. People with brain injuries produce less melatonin at night and spend more time in slow wave sleep, according to a new study.

Australian researchers used a sleep lab to monitor subjects who were recovering from severe brain trauma. The findings were published in the May issue of the journal Neurology.

A small sample of 23 patients volunteered to undergo a sleep study. Each suffered a brain injury an average of 14 months before the study. Their data was measured alongside a control group of 23 healthy people.

The patients produced significantly less melatonin in the evenings compared to healthy individuals. Melatonin is a hormone that regulates tiredness by letting the brain know when it’s the evening and its time to sleep.

Sleep architecture changed after brain trauma and sleep quality rated lower. 24 percent of the experimental groups’ sleep was in the late non-REM stages known as slow wave sleep. Most people spend only about 15-20 percent of the sleep time in this deep sleep.

Those with brain injuries spent more than double the time awake after initially falling asleep. On average, they spent more than an hour awake in bed compared to 27 minutes for the healthy group.

The frequency of mental disorders including anxiety and depression was also higher, possibly due to poor sleep.

The authors of the study theorized head injuries may disrupt the brain structures that produce melatonin, causing a slew of sleep-related symptoms. They said future studies should explore the effectiveness of using melatonin supplements to compensate for the loss in production of the hormone.