There have been 25 schools affected by suicides and sudden deaths since September 2017, it has been revealed.
The figures were released during Stormont's education committee yesterday after SDLP MLA Daniel McCrossan asked what support services were in place for children if a fellow pupil took their own life.
Nicola Topping from the Education Authority (EA) said the body's critical incident response team would help schools in "sudden death type situations".
Mr McCrossan said he had attended three funerals of pupils who had taken their own lives last summer and that could have an impact on schools.
He also described the figures that were released yesterday as "shocking" and proves that mental health is hitting every aspect of society - including children.
"Having spoken to some families and teachers, I know that services are stretched far too thinly and everything should be done to bolster these services given that levels of mental health and suicide are increasing," he said.
"I want to see more investment in mental health services in schools, in tackling bullying and counselling services.
"Children need to have a safe place to be able to open up and receive the necessary care and support." Ms Topping said that the EA's critical incident response team would visit a school after an event such as a suicide to provide support for counselling.
The team provides extra support to the school's existing pastoral care team in the event of the serious injury or death of a pupil, member of staff or member of the school community.
"Over the past three years the critical incident response team has responded to 141 critical incidents," Ms Topping said.
She added that 25 of those were in "sudden-death type situations such as you're describing".
Commenting on the critical incident response team last night, an Education Authority spokesperson said it provides support to all schools following a "sudden event".
"This support is very often required following the death of a pupil of member of staff of the school," the spokesperson continued.
"The nature of support provided for pupils and staff assists them to normalise their feelings and reactions, identify their support network, practice self-care and encourage effective coping skills."
Ms Topping also detailed how many counselling sessions were available to post-primary schools on a weekly basis.
A new Independent Counselling Service for Schools service was introduced in September 2019 at a cost of £23.6m over five years.
In post-primary schools with fewer than 499 pupils, just three pupils per week could receive a counselling session in addition to one 'drop-in' session.
In schools with 500 to 999 pupils, five pupils a week could receive a counselling session, while that rose to eight pupils in schools with 1,000 to 1,499.
In the largest schools, with over 1,500 pupils, 10 pupils could receive a counselling session each week in addition to a drop-in session.