LET THERE BE LIGHT –
Nov. 7, 2025 – Researchers believe that wintertime SAD is caused by reduced daylight, which can desynchronize our internal circadian rhythm from the natural light cycles outside. To fight the dark, the answer is to provide more light where it is missing. The standard treatment for SAD is bright-light therapy with a light box that delivers at least 10,000 lux of light. (Run-of-the-mill indoor lights are typically less than 1,000 lux, while direct sunlight can go up to about 100,000 lux.)
Research shows that light therapy is effective at improving mood and reducing symptoms of SAD in about 64 percent of patients, according to a 2015 study.
For his part, Rosenthal has supplemental light in almost every room of his house.
In the bedroom, he has a selection of lights that can be gradually illuminated, including three large light boxes that can be turned on sequentially to help him greet the day.
The lights are an integral part of other habits that he’s adopted. (In total, he has 13 light-therapy devices of different shapes and sizes in his home.)
