Over 200 children have been admitted to adult psychiatric units over the past three years.
There were more than 80 in both 2017 and 2018 - but this dropped to 50 in the first 11 months of last year to bring the total to 216.
The HSE says kids are only admitted to adult units after efforts to place them in child and adolescent facilities are unsuccessful.
Patricia Casey, a consultant psychiatrist in the Mater Hospital, says sometimes doctors are left in a difficult position:
"A child might be acutely suicidal and if they arrive at the emergency department, which is where they usually come to, or if they are sent up there," she said, "the adult psychiatrist would see them and might feel that they needed admission to protect their own lives."