Disturbing: Pictures drawn by children in detention show the deep trauma many of them have suffered. Photo: Supplied
High school student and Afghan refugee Bashir Yousufi still feels sadness about the trauma he experienced while waiting to be processed.
He had already lost his father to the Taliban and his mother to illness before he arrived on Christmas Island as a 14-year-old unaccompanied minor in 2010.
If you're in Afghanistan [and] the Taliban want to kill, they just shoot you and you will die easily. But in Australia, they will kill you slowly with your mind.
He spent almost a year in cramped accommodation with six other children, not knowing what the future held.
Sadness: Former detainee Bashir Yousufi. Photo: Nick Moir
In a statement tendered to the Australian Human Rights Commission inquiry into children in immigration detention, the now 17 year-old HSC student at Holroyd High said his memories continue to haunt him.
''If you're in Afghanistan [and] the Taliban want to kill, they just shoot at you and you will die easily. But in Australia, they will kill you slowly with your mind.''
During the hearing it also emerged that, as of this school term, children who turn 18 while still at school are no longer removed from the education system.
Cry for help: Another drawing by a child in detention. Photo: Supplied
Dorothy Hoddinott, the principal of Holroyd High, told the inquiry the policy change followed a complaint she lodged on behalf of one of her pupils.
Out of the school's 530 students, 44 are living in community detention, all of whom are unaccompanied minors. A further 36 are on bridging visas.
Mrs Hoddinott told the inquiry any children who had spent time in closed immigration detention arrived at the school passive, depressed and slow to react.
''A lot of them have difficulty with concentration, with focusing on their school work … some of the students have memory loss,'' she said.
Immigration Minister Scott Morrison confirmed the department had reviewed its schooling policy and was allowing ''greater flexibility''.
The inquiry, headed by AHRC president Gillian Triggs, is investigating the impact of detention on children, some of whom are as young as six weeks old. There are 929 children in detention in Australia and a further 177 in Nauru.
The inquiry heard of harsh conditions at Christmas Island, which delegates inspected last month.
Ms Triggs said she saw children who were ''manifestly ill'' and not receiving adequate medical care. At Villawood, she observed an ''environment of constant surveillance, supervision and harassment''.
Paediatrician Karen Zwi was also left troubled by what she saw on Christmas Island, including children with infected sores who were crying out in pain caused by tooth decay. Babies are unable to crawl because the ground is so rough and the only playground is unusable during the day due to the extreme heat.
New mothers are forced to queue up for strictly rationed nappies, baby wipes and powdered milk, with staff telling them constantly they will never be resettled in Australia.
''People describe this as cruel, torture. Those are the words they use,'' Professor Zwi said.
Family and child psychiatrist Sarah Mares shared pictures drawn by children in detention, one of which showed a jailed figure with no mouth or hands but tears running down its cheeks.
Representatives from the Department of Immigration told the inquiry that children did have access to adequate medical care and support for mental health problems.
The HRC is expected to hand down a report on the inquiry in September.