ChildLine received almost 50,000 calls for help from children and young people in Northern Ireland during Christmas.
Family relationships, bullying and depression remained the primary concerns of those who contacted the Belfast and Foyle centres.
Esther Rantzen, president of ChildLine, said: "These figures clearly demonstrate how many distressed children depend on ChildLine, especially at times such as Christmas, which is often particularly difficult for vulnerable young people."
She continued: "ChildLine is a vital lifeline for thousands of young people who desperately need support and advice on suicidal thoughts, self-harm, sexual abuse and mental illness."
The number of contacts by telephone, email or online chat to ChildLine totalled 48,751 over the 12-day festive period from Christmas Eve and figures showed a 50% increase in the number of counselling contacts on Christmas Day compared with the previous year.
One caller to ChildLine in Belfast said: "My brother is thinking of running away because we get hit by our parents. We get hit randomly - hitting a person for discipline is what my dad does.
"I self-harmed tonight. I hurt myself and I am angry that the marks disappeared - I wanted the marks to stay."
Across the UK, there was a dramatic increase in depression and mental health-related counselling, which increased by 103% compared with Christmas 2010. Counselling for self-harm and suicide also increased by 62% and 57% respectively. Visits to the ChildLine website increased by 57% last year.