More than a third of young people living on the street have been in state care, it emerged today.
Levels of drug use are extremely high among the state's homeless youth, with half hooked on heroin.
Poor nutrition, substance use and exposure to the elements have also made those who slept rough prone to infection and respiratory problems including asthma, bronchitis and pneumonia.
The figures, compiled for a study on youth homelessness, show the importance of understanding and planning for the needs of homeless children in Ireland, said Sylda Langford, of the Office of the Minister for Children.
"The aim of this research was to gain an understanding of youth homelessness in Dublin city, based on the accounts of the 40 young people who are living out of home — either on the streets, in hostels or in other unstable living situations," said Ms Langford.
"Few issues could be of more critical concern than that of homelessness.
"One of the disturbing findings of this study was that 16 of the 40 young people interviewed reported a history of state care."
Youth homelessness is primarily an urban phenomenon and Dublin city has consistently recorded the highest number of homeless youth nationally.
The survey revealed that after a young person left home 33.3 per cent had stayed in an adult hostel at some time, 60 per cent had slept rough and 45 per cent had spent time in juvenile detention or prison.
A large number of youngsters have even admitted suffering emotional distress and sadness about their situations, past and present, and several experienced more profound crises linked to the absence of a stable home and the ongoing trauma of early life experiences.
Ms Langford told the launch of a report in the National Children's Strategy Research Series, entitled: Understanding Youth Homelessness in Dublin City, it was evident many under 18 had a more positive experience of the homeless services than their older counterparts, who became homeless before a Youth Homelessness Strategy was drafted in 2001.
"The risks that homeless young people face can be unimaginable," said co-author Dr Paula Mayock.
"This study uncovers the complexity of the causes of youth homelessness and demonstrates how homelessness impacts on the lives of young people.
"Homelessness is a chronic stresser, a dehumanising experience and can have serious negative consequences for young people' concluded Dr Mayock."
