The Samaritans expect to take 10 per cent more calls than usual over the Christmas and new year period as people experience depression amid the celebrations.
The organisation said its experience showed that "depression and even suicidal thoughts are real emotions for some in the middle of all the celebrating".
It said the message was that people did not need to face these feelings alone and it was planning to operate its helpline (1850 60 90 90) throughout the holiday period. It was particularly concerned for younger men who were at a higher risk of committing suicide.
The group has started an advertising campaign called "Time Please " to "get across the serious business that people will feel low at this time of the year and they can call to talk about it". It has also issued several pointers, endorsed by independent experts, on how to recognise and deal with depression.