The number of suicides among young people known to social services doubled last year as waiting lists for mental health care worsened.
The 2014 findings of the National Review Panel - an independent investigation group set up by the Government in 2010 - uncovered an ongoing series of failings in child welfare and protection services.
There were 26 deaths of vulnerable teenagers and children last year - the highest since 2010. Eight took their own lives, compared with four in 2013.
Eight died from natural causes, but five were killed in traffic accidents, one died of an overdose, and two were murdered.
A review of 12 child deaths found one suicidal girl was unable to access psychiatric help just days before her death.
Helen Buckley, chair of the review group, said it found that alcohol, drug abuse and domestic violence were issues in half the cases.
Other serious problems uncovered were parents suffering from mental health or intellectual disability.
However, she said: "A strong theme was the difficulty of accessing appropriate psychology and mental health services for suicidal young people."
There were long waiting lists, of up to two years, for psychology services. The treatment was time-limited, she added.
Some cases were wrongly placed in the child welfare division rather than the more high-risk child protection category.
Information held by some services involved with families was not shared by other agencies.
One child had 18 social workers in 10 years, another had eight over 10 years and another four in five months.
"In some cases the child who died had not been the focus of any attention but had been in the background," she added.
"Families did not always feel their concerns were heard.
"In two cases, families predicted the tragic outcome but felt they could get nobody to respond to them.
"In another case, a mother phoned the social work department 10 times before the case was allocated."
She added: "In one case, a family support service had to make many requests for a case to be allocated as serious risks were emerging."
Risk was not always recognised - sometimes because full information was not shared, but on other occasions it was not considered a possibility .
The review group said there needed to be proper channels of communication between child welfare and protection services and adult mental health services. There are around 70,000 staff in the HSE whose work brings them into contact with children, or adults who have children. There needs to be investment in training to highlight their responsibilities in bringing child protection concerns to the attention of authorities.
Tragic deaths of the children known to social services
Cal, a member of a Traveller family, died in a domestic accident involving a car seat months after being found in a neglected state. The social work department had been notified of concerns when Cal was 18 months, 20 months and 22 months. There is no record of response to the first two and the case was then placed on a waiting list. A social worker visited the family.
Karen took her own life at the age of 15. She had a difficult relationship with her mother. The social work team visited the family but Karen was not always seen individually. Ultimately, it was decided to allocate the case to a newly-appointed social worker but Karen died before this could happen.
Donal died in a car accident shortly before his 18th birthday. He had been involved with numerous services. He could be aggressive and destructive at times. He was allocated a specialist adolescent social worker, in addition to his own social worker. At 17, he was placed in an emergency hostel.
Lucy was just 10 months old when she died. A post-mortem examination concluded her death was consistent with sudden infant death. Her mother had a learning disability and had spent time in care. She agreed to a support plan offered by a voluntary agency and her public health nurse.
Names have been changed