High school student Bashir Yousufi is grateful for his life in Australia but the Afghan refugee still harbours deep sadness about the trauma he was forced to endure 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.

Disturbing: Pictures drawn by children in detention show the deep trauma many of them have suffered.

He spent almost a year in cramped accommodation with six other children, not knowing what the future held.

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.