With Christmas and New Year celebrations behind us, the cold, dark days of January can really get us down. January 16th has been dubbed by experts as the “most depressing day of the year.” But where does the term come from, and what can you do to combat the blues?

The term Blue Monday was coined by psychologist Dr. Cliff Arnall, who worked out a formula to show how the third Monday in January is especially bad. It takes into account factors including the average time for New Year's resolutions to fail, the bad weather, debt, the time since Christmas, and motivational levels.

On average, 1 in 15 people become depressed in winter and suffer from Seasonal Affective Disorder (SAD). It is believed that the problem is related to the way that the body responds to light. The main theory suggests that a lack of sunlight may stop a part of the brain called the hypothalamus from working properly. This could impact the production of the hormone melatonin, which makes you feel sleepy. People with SAD produce it in higher levels than normal. The production of serotonin could also be affected, further impacting mood, appetite, sleep, and feelings of depression.

What can you do to feel better? Dr. Arnall said that people should embrace the opportunity to turn over a new leaf. “Whether it's embarking on a new career, meeting new friends, taking up a new hobby or booking a new adventure, January is a great time to make those big decisions.”