Around 30 to 35% of adults experience brief symptoms of insomnia, or the inability to fall or stay asleep, during their lives. These values continue to increase: around five million more Americans reported having trouble falling or staying asleep in 2017 in comparison to 2013. Adults who get an insufficient amount of sleep are more likely to report life-threatening disorders such as heart attack, stroke, diabetes, and depression. The fatigue, poor concentration, and low motivation and energy associated with a lack of restful sleep also lowers the quality of life and increases the risks of accidents in day-to-day life. By ensuring that everyone gets 7-8 hours of good-quality sleep, the prevalence of these unhealthy habits and disorders can be reduced.
The molecular mechanism for the sleep-wake cycle is best described as a “flip-flop switch”. When you’re awake, a group of brain cells called orexin neurons is activated; these brain cells are responsible for keeping you in a wakeful state. As it gets darker and closer to the time to sleep, the switch flips, and your body produces molecules such as melatonin and adenosine. Melatonin works to lower your body temperature and relax your body and mind before you sleep; adenosine, however, directly inactivates the orexin neurons, which reduces your alertness. In some patients with insomnia, this switch doesn’t work the way it is supposed to. The orexin neurons are hyperactivated, so even when melatonin and adenosine are made, these neurons are unable to be turned off. If they are able to be silenced enough to allow insomniacs to sleep, they can still get reactivated easily, causing the person to wake up easily and preventing them from getting restful sleep.
The sleep-wake cycle can be described as a “flip-flop switch,” which doesn’t work correctly in patients with insomnia.
Image Source: JMWScout
Scientists have developed and tested a new drug, daridorexant, that was recently approved by the FDA to treat insomnia in adults. Unlike melatonin pills, which aim to relax your body to get ready for sleep, daridorexant works to block the orexin neurons and therefore prevent excess arousal and alertness. During the clinical trial, patients with insomnia took either a placebo or 50 mg, 25 mg, or 10 mg of daridorexant once every evening for three months. Patients recorded their total sleep time, were monitored to view their sleep induction (their process of going to sleep) and maintenance, and filled out a survey detailing their daytime sleepiness and fatigue.
The 50 mg and 25 mg treatments significantly reduced how long it took for patients to fall asleep and how many times they woke up during the night in comparison to the placebo, while the 10 mg treatment had no effect. The 50 mg dose also led to less reported fatigue and drowsiness during the day, overcoming one of the biggest drawbacks of the lack of adequate sleep. The most common side effects were also not very severe; most patients only experienced a headache and a cold. With this new drug, more people may get the sleep they need to have the best quality of life possible.
Featured Image: Antonioguillem
