Entrepreneurs are notorious for burning the midnight oil. Founders often gloat about 24-hour coding sessions or the late-night hours they keep to get the job done. But take note, night owls: According to a study, a lack of sleep can take a toll on your mental health.

Researchers at the Broad Institute at MIT and Harvard, and the University of Colorado found that people who go to bed and wake up earlier have a significantly lower risk of major depressive disorder (MDD). This study examined data from nearly 840,000 adults in the UK Biobank (UKB), genetic data from the DNA testing company 23andMe, and sleep tracking data from more than 85,500 people. The researchers used a unique statistical technique called mendelian randomization (MR) to determine if a person's diurnal chronotype--the natural tendency to sleep at a certain time--could cause major depressive disorder.

Next, the researchers reviewed hospital record-based MDD diagnoses in the UKB. What they found was fascinating. According to the study, being a morning person and going to bed one hour earlier and waking up one hour earlier significantly reduces your risk of major depression. But why? Your circadian clock, which influences sleep timing, is tightly regulated by external environmental cues. Of those cues, light is the strongest.

Light is an alerting signal, and as research demonstrates, it entrains or aligns your internal biological clock with your environment around you. When you view light early in the morning, it impacts a cascade of hormonal and neurological events that directly affect your mood, alertness, and ability to fall asleep at night.

All said, if you are a night owl or have become a night owl by habit, here are three simple tips to help you go to bed earlier and be more productive during the day.

View light upon waking

Get as much natural light exposure as possible upon waking. This improves your alertness during the day and helps you fall asleep faster at night by regulating the rise and fall of cortisol and melatonin.

If it's dark when you wake up, safely view artificial light, and then at sunrise, try to get at least 10 to 15 minutes of sun exposure. If you find it challenging to get 10 to 15 minutes at one time, then microdose short five-minute sun exposures and accumulate as much time as possible before midmorning.

Exercise early

Exercise is a potent stimulus for changing your internal clock. Even a 15 to 20 minute brisk walk outside can improve your alertness early in the day and help shift your biological clock. If you can combine exercise with bright light exposure, that's even better.

Avoid evening light exposure

If the light is an alerting signal in the morning, it's logical to assume it's an alerting signal in the evening. Therefore, when the sun goes down, you should change the environment of your home to match the natural environment outside. Dimming overhead lights and reducing your exposure to screens are excellent ways to do this.

Finally, blue light blockers or glasses won't save you. Light, of all wavelengths, is the issue, not just blue light. Wear them if you want, but you are better off dimming all lights so you can easily transition to sleep.

Make the shift and protect your mental health. You can be productive, creative, and successful without working absurdly late hours.