Childline answered almost 700 calls from children and young people on Christmas Day, many of them expressing feelings of isolation, sadness and loneliness.
The organisation, which was set up by the Irish Society for the Prevention of Cruelty to Children, also received 134 texts from young people seeking one-to-one support.
Childline says the figures represent a significant increase on previous years and have prompted the organisation to express concern about the levels of mental health problems being experienced, especially by teenagers.
Childline has now called for out-of-hours social support services to be extended to teenagers and their families. According to Childline's Deirdre Swords, the increase in contact regarding mental health issues indicates young people are increasingly vulnerable and in need of support.
"We can see from our 2007 service statistics that young people are increasingly seeking support on serious mental health issues.
"Childline's automated text service received 8,260 texts regarding the issue of suicide and loneliness and the telephone service recorded 1,390 phone calls."
Ms Swords said the "worrying climb" in the statistics was "heightened and evident" on Christmas Day when the organisation had 31 volunteers and staff who gave up part of their day to answer calls.
