Volunteers achieve breakthrough insights in sleeplessness, trauma and depression

Some ten thousand volunteers, brought together by the internet platform ‘Slaapregister.nl’ (the Netherlands Sleep Registry), have achieved a scientific breakthrough. Together with researchers from, among other institutions, the Netherlands Institute for Neuroscience, they found an important clue for the reason why sleeplessness is more susceptible to depression or posttraumatic stress syndrome. Improved sleep may help to prevent depression – an item that is high on the agenda of Edith Schippers, the Dutch Minister for Health, Welfare and Sport. This discovery was published on 8 February 2016 in the reputable scientific journal PNAS.

Hyper

Not only is chronic insomnia one of the most common health problems, it is also the key risk factor for developing depression, and it renders people vulnerable to posttraumatic stress disorder. Insomniacs experience many short disruptions of their sleep at night. People who have a short but uninterrupted sleep are sleepy during the day. However, chronic insomniacs are surprisingly “hyper” during the day. Heart rate, metabolism, stress hormones, thoughts and emotions, irritability: almost everything that can be measured in an insomniac is heightened. In the longer term this is exhausting and it could lead to depression.

Sleeping on it

The crucial question was why insomniacs are so hyper. Earlier studies have shown that Rapid Eye Movement (REM) sleep helps to process emotional experiences. Participants in the sleep registry program therefore kept a record of how long it took them to get over a distressing, personal, shameful emotional event. As expected, ‘sleeping on it’ helped good sleepers to release the tension quickly. But the restless REM sleep of the insomniacs turned out to be a hindrance when it came to the processing of emotional experiences. In these individuals the tension lasted for days. And the more often this happened, the greater the likelihood that they ended up in the characteristic ‘hyper’ state.

People who suffer from chronic insomnia, depression or posttraumatic stress syndrome all show the characteristic restless REM sleep. Treatment for these kinds of disorders thus requires a way to stabilize sleep in order to prevent things from getting worse.

The sleep registry (slaapregister.nl)

The researchers of the Netherlands Institute for Neuroscience hope that both current and new volunteers will continue to fill out the questionnaires on Slaapregister.nl: “In the past year, the Dutch population has already helped to compile the Nationale Wetenschapsagenda (the Dutch National Research Agenda). Here they show that they are also able to achieve a scientific breakthrough. We think that together they may help us crack exactly how this ‘hyper’ state leads to depression. And whether depression can be prevented by a more stable REM sleep”, according to Rick Wassing, first author of the paper in PNAS.