Overview
- The label was created in 2005 by psychologist Cliff Arnall for Sky Travel, using a pseudo-formula that scientists and charities have long rejected as baseless.
- Monday, January 19, 2026 was widely billed as the third Monday "Blue Monday," but reporting stresses there is no evidence a single day is the year's saddest.
- Mind and the Samaritans warn the concept trivialises depression, with the Samaritans branding it "a load of rubbish" and promoting Brew Monday to encourage conversations.
- Clinicians highlight that Seasonal Affective Disorder is real and treatable, recommending light exposure, outdoor activity, routine, social connection, CBT, light therapy and medication when needed.
- Commentators note the idea has been amplified by marketing and can act as a self-fulfilling prophecy, and Arnall has since urged people to refute it.