The charity is set to end a busy year by being on call for 123,000 hours over the Christmas period to listen to those having a tough time.
Volunteer Arup Sen, 49, told the Press Association: "Last year there were some issues around money - with the adverts they're being encouraged to spend both on Christmas presents, on food, and they can't, they want to but they can't."
He said: "There was sort of a pressure on people to feel happy or feel good or behave in a certain way because it was Christmas."
He added that some people who call over the festive period can feel "embarrassed or disempowered" after their Christmases do not match up to those traditionally portrayed in adverts or films.
Last year the service answered 230,000 calls between December 18 and January 1. They respond to more than 5.7 million calls over the course of a year.
The charity said that they expect the key issues for those suffering over Christmas to include mental health problems, isolation and loneliness, relationships, as well as drug and alcohol misuse.
Ann McLaughlin, a branch director for the Samaritans in Ealing, London, looks after 150 volunteers.
She said: "I gather there's a lot of distress in many households ... because people are stuck together in the same room, tanked up on beer, stuffed with food and they don't really like each other."
Diana Lau, who works with homeless people for Crisis as part of her Samaritans work, said she "wouldn't feel right" without volunteering over Christmas.
She said: "This is doing something, maybe taking me out of my comfort zone a little bit but it's something I can do to just give a little bit of myself."
Dave Hall, a 34-year-old web designer, is due to work an overnight shift this Christmas.
He said: "Night shifts are always some of the hardest shifts, but also some of the most rewarding shifts because people who are calling at four in the morning generally have some pretty real problems that they want to talk about.
"It isn't a happy time for everyone, it's not always been a happy time for me."
The Samaritans can be contacted any time for free on 116 123.