Dr Cliff Arnall of Cardiff University has christened January 22 'Blue Monday', when post-Christmas fatigue kicks in, resolutions fall by the wayside and spring seems ages away.What's more, the academic says the feeling will last all week as the lethal combination of miserable weather and astronomical credit card bills affects even the super-happy among us.
Dr Arnall formula - 1/8W+(D-d)3/8xTQMxNA.
It factors in the dreariness of the (W)eather, the arrival of Christmas bills or (D)ebt, minus monthly salary (d), (T)ime elapsed since Christmas and the failure to keep a New Year's resolution or to (Q)uit a bad habit, low (M)otivational levels and the need to take action (NA).