Some of the factors measured by the formula include weather, people’s financial situations in the post-holiday slump, and a lack of motivation. But the science behind the day—and the formula—has since been questioned, while some psychologists have criticized the phenomenon for trivializing depression. Big number: While Blue Monday has largely been debunked as a myth, Seasonal Affective Disorder (SAD), also known as winter depression, is real. According to the NHS, its causes aren’t fully known, but it is linked to reduced sunlight exposure during the colder months. It is thought to affect 3% of people in the U.K., while 10 million Americans are believed to live with the symptoms.

Source: Forbes January 20, 2020 11:49 UTC