Feeling down today? It may not just be lingering depression from last week's Inauguration. A British psychologist has developed a mathematical formula that identifies January 24 as the most depressing day of the year.

The model is: [ [W + (D-d)] x TQ ] divided by [M x NA]. The seven variables are: (W) weather, (D) debt, (d) monthly salary, (T) time since Christmas, (Q) time since failed quit attempt, (M) low motivational levels, and (NA) the need to take action.