It's not just you: yesterday really was depressing By Catriona Davies (Filed: 24/01/2006) If you woke up yesterday feeling gloomy and found that, from then on, things got worse, there may be an explanation. According to one academic's calculations, yesterday was the most depressing day of the year. Cliff Arnall, a psychologist at Cardiff University who devised the formula, blamed a combination of debts, failed New Year's resolutions, the cold, grey weather and the length of time since Christmas. "For most people, there's a realisation by the third week of January that spending on sales items needs to be stopped...