20,000 mental health appointments for children and adolescents were unattended in 2018

10% of Child and Adolescent Mental Health appointments were unattended last year.

That is according to figures obtained by Newstalk through a Freedom of Information request from the HSE.

It means people did not attend over 20,000 CAMHS appointments in 2018.

The HSE does not keep records of registered reasons for cancelled or unattended appointments.

"There are months, if not years, of waiting lists for some people and I just think that all of these appointments that are just going by the wayside with people just not bothering to ring up, it would shorten the waiting lists," said one mother who has used the CAMHS service.

"It might only be a small amount but it could still be one more person at least getting in there."

Independent Senator Joan Freeman - a former CEO of Pieta House - says there can often be a number of reasons why people do not attend.

"There are people who ring up and try to cancel an appointment and they can't get through, they could be phoning for ages," said Ms Freeman.

"Then, they get a letter saying that you did not appear, you did not attend.

"But you have got to realise that when someone looks for an appointment, they may not get seen for months or for years and at that stage the chances are that something has happened - they have moved on, they have gone to a private source or the crisis might have passed.

"Now that still doesn't give anybody the right not to cancel."