If you feel moody or haven’t been sleeping well, it may be time to see yourself in a new light, literally. Light helps regulate the natural rhythms of our body and mind, and not getting enough or the right kind of light can impact our health in surprising ways.
“Human beings evolved under the day-night cycle,” said Richard Schwartz, MD, an associate clinical professor of psychiatry at Harvard Medical School. “It is the natural time-keeper that sets our biological clocks within our brains and organs throughout the body.” When those clocks, known as circadian rhythms, get disrupted, it can affect our sleep, mood, and cognitive performance.
Dr. Schwartz points out that modern life does not lend itself to the regular cycle of sunlight and darkness that set our ancestors’ internal clocks. “Most of our lives today are spent with artificial lights indoors,” said Schwartz, who recently helped develop a wearable device that tracks a person’s light exposure. “Their timing and brightness are not what we need to function at our best.”
That’s where bright light therapy can help. Also known as phototherapy, it involves exposure to specific levels of light under controlled conditions. It’s a common treatment for seasonal affective disorder – the “winter duldrums” that set in when the days grow short during fall and winter.
“In many cases, light therapy can replace medication for people with seasonal and nonseasonal depression, bipolar depression, and depression during pregnancy,” said Michael Terman, PhD, director of the Center for Light Treatment and Biological Rhythms at Columbia University Medical Center and author of Reset Your Inner Clock. “In other cases, adding light therapy can boost the effect of drugs alone.”
Research suggests light therapy can be effective in treating insomnia, attention deficit hyperactivity disorder (ADHD), and dementia. Studies have shown that it can improve motor function in patients with Parkinson’s disease.