The number of children who have been prescribed psychiatric medication has increased by nearly 500% over the past decade.
The rise amounts to more than 5,300 medical-card patients.
New figures released by the HSE under the Freedom of Information Act shed a light on the number of people in Ireland who are being treated with medication for mental health issues.
In 2009, 1,150 children under 15 were prescribed psychiatric medication under the medical card scheme.
But this has increased noticeably every year since then, rising to just under 6,500 children last year.
Brendan Kelly, Professor of Psychiatry at Trinity College Dublin, says a recruitment crisis in the HSE's child and adolescent services is a factor in the trend.
"We know referrals to child and adolescent psychiatry have increased by 40% over the past six or seven years or so," said Prof Kelly.
"And the child and adolescent mental health services have just 57% of the staff that the national policy recommends they should have.
"So in this situation, you often see an increase in both referrals and an increase in prescribing."
The trend is out of sync with the same stats for the general population, which has seen only a 12% rise in the same time frame.