Overview
- Reporters trace the idea to a 2005 formula by psychologist Cliff Arnall that was created for a travel promotion, not scientific research.
- Brands and social media recycle the label each January, turning it into a cultural ritual despite the lack of scientific basis.
- Experts distinguish the myth from seasonal affective disorder, which features recurrent winter depressive episodes with symptoms like oversleeping, low energy and carb cravings.
- Prevalence varies by latitude, with estimates cited for Italy of roughly 5% severe cases and 20% milder forms, and broader winter blues affecting up to one in three in the Northern Hemisphere.
- Evidence supports bright light therapy—often used daily through winter—with cognitive‑behavioral therapy and antidepressants considered for more severe presentations.