After a long day or a stressful situation, you might hear the advice of “just sleep it off” or “you’ll feel better in the morning.” And while it might seem like an invalidating, oversimplified recommendation, it has some accuracy: often, our bodies and minds are better after a good night’s rest.According to Josef Newton, founder of the health anxiety app Condri, this morning improvement comes from sleep repairing emotional regulation, the cortisol awakening response, and activating the circadian system.“Analyzing problems at night means you are using brain power whilst your mental and physical resources are at their lowest. There are also few distractions, and your access to reassurance is limited,” he says. “When you ‘sleep on it,’ it doesn’t remove the crisis, but it does alter the way in which your brain is interpreting it.”Newton breaks down the three science-backed reasons things always seem better in the morning.1. Sleep Deprivation Activates the Body’s Stress Response According to Newton, a brain-imaging study by Current Biology found that sleep-deprived individuals show over 60% greater reactivity in the amygdala, the part of the brain that processes emotions and detects danger. The research also found that lack of sleep may weaken the connection between the amygdala and the medial prefrontal cortex, which helps regulate emotions and decision-making.As such, sleep deprivation can do a great deal of harm to the body, often activating the fight-or-flight response. Naturally, a heightened nervous system can lead to hypersensitivity and reactivity.“Essentially, symptoms of the brain’s fight-or-flight response increase as the part responsible for perspective becomes less able to moderate it,” says Newton. “For instance, you may interpret a minor disagreement as a catastrophic relationship breakdown or a curt work email as the beginning of disciplinary action.”“Late-night overthinking is a great actor as it stirs feelings that are very real,” Newton continues. “It’s important to remember that the strength of the emotion doesn’t prove that your interpretation of the scenario is accurate. Ultimately, sleep paves the way for the brain’s ability to regulate its alarm responses.”2. Cortisol Delivers a Natural Wake-Up CallContrary to what you might hear on the internet, cortisol is an essential stress hormone that assists with the body’s wake cycle. Cortisol naturally rises in the morning, providing us with energy as we start our day.“Morning time creates a natural uplift that’s likely to increase our confidence in tackling the problems that felt disastrous the night before,” says Newton. “The situation may be unchanged, but your perceived ability to cope with it can be different.”“It’s also worth noting that chronically disordered sleep may not experience the cortisol wake-up,” he adds. “For instance, shift workers, new parents, and people with disrupted sleep may not experience this neat morning improvement. Some people with depression also feel worse in the morning, so the phenomenon is common rather than universal.”In other words, good-quality sleep is crucial to our mental and emotional well-being.3. Morning Sheds Light on a New PerspectiveNever underestimate the power of morning light and a new day.“Light gives the brain its strongest ‘daytime’ cue, while getting out of bed changes the environment around a worrying thought,” says Newton. “Daylight, movement and contact with other people introduce new information, which can interrupt the loop and restore proportion.”This is where the advice to “sleep on it” comes into play.“The phrase ‘things will look better in the morning’ should never be used to minimize genuine distress,” says Newton. “Sometimes the problem is still painful in daylight, and support is needed. But when tiredness has turned uncertainty into catastrophe, morning can provide something valuable: a rested brain, a body prepared for action, and enough light to see the situation in proportion again.”The post 3 Reasons ‘Sleep on It’ Is Actually Pretty Good Advice, According to Science appeared first on VICE.