Today, Monday, January 19, marks what has been popularly dubbed “Blue Monday,” often described as the most depressing day of the year. The term was first coined in 2004 by psychologist Cliff Arnall, who was asked by the British travel company Sky Travel to devise a “scientific formula” linking January gloom to increased winter travel bookings.

[W + (D – d)] X TQ / M x Na

Arnall’s formula attempted to combine weather (W), debt (D), monthly income (d), time since Christmas (T), failed New Year resolutions (Q), low motivation (M), and the feeling of needing to take action (Na) into a single calculation. While catchy, this approach has been widely criticized by scientists as pseudo-scientific.

Despite its commercial origins, the concept resonates with real seasonal challenges. Many people experience lower moods in January and February due to winter weather, post-holiday fatigue, and the frustration of unmet New Year expectations. Arnall has emphasized that the term was never intended to stigmatize this day, but rather to encourage a positive outlook and new beginnings.

The timing of Blue Monday also overlaps with a period when Seasonal Affective Disorder (SAD), or winter depression, can affect some individuals. Symptoms of SAD may include low energy, excessive sleep, increased appetite and carbohydrate cravings, weight gain, and social withdrawal. Though less common in summer, this pattern of mood change highlights the physiological effects of reduced sunlight during winter months.

Experts advise viewing Blue Monday with caution: while it may capture the public imagination, it is not a scientifically proven phenomenon. Instead, it serves as a reminder to pay attention to seasonal mental health, prioritize self-care, and seek professional support if mood disturbances persist.