Monday, 22 January, is the most depressing day of the year according to the Samaritans.

As part of a campaign to raise the awareness of the charity, Dr. Cliff Arnall of Cardiff University first defined blue Monday. He devised the mathematical equation:

[W + (D-d)] x TQ
M x NA

The model was broken down using six immediately identifiable factors: weather (W), debt (d), time since Christmas (T), time since failing our new year's resolutions (Q), low motivational levels (M) and the feeling of a need to take action (Na).

The equation calculates that Monday 22 January is officially the worst day of the year, when the Christmas glow has faded, New Year’s resolutions have been broken, cold Winter weather has set in and credit card bills will be landing on doormats.

The Samaritans is encouraging people to reach out for help before problems escalate and stave off seasonal depression by following eight key tips: Try something new, get physical, contact a friend or relative, take a break, be nice to a stranger, pamper yourself, plan something new and share your thoughts.