American Journal of Epidemiology

Low light in your room (think street light making its way through your blinds) may affect melatonin production, but it might also be problematic to your mental health.

This study looked at the effect of light in the bedroom and how it impacts depression.

Researchers found that exposure to five lux or more of light significantly increased the risk of depression when compared to sleeping in a totally dark room. That’s alarming because 5 lux is less than the amount of light a candle produces.

This study was done on over 800 adults, with an average age of 71 years. That said, younger adults have a much higher capacity for light retention, even when their eyelids are closed, suppressing melatonin and ruining chances for a good night of sleep. This effect likely compounds over time, increasing your odds for developing depression.

Takeaway: It’s important for kids, teens, and younger adults to sleep in a completely dark room. This ensures maximal melatonin production, while decreasing the likelihood of sleep-deprived depression. Using blackout shades, turning off all electronics, or wearing a sleep mask should do the trick.