SOME are hardened by abuse that has forced them to grow up too soon. Neglect has left others without the most basic social skills.
Their common bond — a substance habit born out of a life lived in the shadows — has brought them to the only safe space they have ever known.
In an unassuming building at the city end of Brunswick Street, Fitzroy, a drop-in centre run by the Youth Substance Abuse Service is literally saving lives.
Here, their habit does not define them. Those with adult problems, who sell their bodies on the street, can be children.
When the doors open at midday, youngsters struggling with alcoholism, inhalant abuse and other drug addictions are waiting. Some are as young as 12.
When the day program began a decade ago, heroin was the main problem. Now, overwhelmingly, it is alcohol.
The number of young people the service treats for alcohol dependency has doubled since 2001.
"We'll get daily users who can be drinking anything from a slab of beer to one, two or three bottles of spirits with very little break in between," senior program development worker Penny Rickard said.
About 30 people under the age of 21 visit daily. The centre does not allow substance use, but it is a safe place to go if users have consumed too much.
"It comes down to harm minimisation and making sure that young people are safe," said Ms Rickard. "If they think they've overconsumed or that their health or their life may be at risk, they know they can come here and we'll take responsibility and care for them."
About 80 per cent of visitors are homeless. Their substance problems often begin after early childhoods defined by physical and sexual abuse, family breakdown and neglect.
For many, the centre offers their only food for the day, a place to shower, wash clothes and make a phone call. Staff help connect them with other welfare services. A doctor who visits three times a week helps those at high risk of mental health problems, sexually transmitted infections and the myriad consequences of sleeping rough.
A common theme for children who have a background in the child protection system is a family history of substance abuse, Ms Rickard said. "These young people might be second, third, fourth-generation substance users."
Staff try to help those with the most acute addictions get specialised help, but funding for youth drug and alcohol services is limited. The Youth Substance Abuse Service, which is the largest provider in Victoria, seeing more than 1500 people a year, has just 37 residential withdrawal or rehabilitation beds and 15 supported accommodation beds across the state.
The Fitzroy day centre opens five days a week for up to six hours a day. After their evening meal, the youngsters are back on the streets. "It's heartbreaking at the end of the day, closing the doors and knowing that they may be sleeping under a bridge," Ms Rickard said.
author: Jill Stark