The former Muslim extremist has suffered panic attacks and has ventured into the sunshine, in the prison yard, only once since his return to Australia in May this year to serve the balance of his nine-month sentence at Yatala Labour Prison in Adelaide. He could not cope and preferred the enclosed prison and artificial lighting, where he felt more safe.
"He tried to go out but he just said everything closed in on him," his father, Terry Hicks, told the Herald.
Hicks, 32, is due to be released under a control order on Saturday. But he is psychologically unprepared for freedom and is so lacking in confidence and social skills that he may refuse to clear his name through a Federal Magistrates Court appearance. In the absence of evidence to the contrary, the court has branded him a highly trained terrorist who is a risk to Australians and a resource for extremist groups.
In a serious sign of the readjustment problems he faces, Hicks was taken out of Yatala prison to the northern suburban Holden Hill police station in early November as part of the lead-up to his release. The trip had to be aborted because Hicks suffered a panic attack, believing he was back in the hands of the US military, his father said.
The Melbourne forensic psychiatrist Paul Mullen, who assessed Hicks at the Guantanamo Bay prison for terrorists in February 2005, said the confinement, institutionalisation and the removal of all initiative would have induced agoraphobia, obsessional behaviours and irrational fear.
Terry Hicks, who saw his son twice at Guantanamo Bay and has visited him regularly at Yatala, said: "It was not good - he had an anxiety thing. They told him he had no choice, he had to go [to Holden Hill] and they put him in the van and took him away. He just regressed back to Guantanamo Bay and he had such anxiety they had to bring him back."
Hicks's agoraphobia and panic attacks are hallmarks of prisoners who have spent prolonged periods in confined isolation. Professor Mullen said he would be suffering psychological damage from his trauma, which included being imprisoned in a container in the hot sun, believing he had been left there to die.
"Your horizons shrink and shrink and your world becomes your cell and everything outside of it becomes increasingly unfamiliar and frightening," Professor Mullen said. "They become not just de-skilled but they lose all of the ease with which we deal with strangers and strange situations. Take them out in the street and they become terrified. Give them a simple task to do like buying something in a shop and it is just overwhelming, difficult and confusing."
the strength to challenge aspects of the control order against him when it returned to court in February remained to be seen.
Hicks has been visited in prison by friends and family, including his children, Bonnie, 15, and Terry, 13.
Under the deal Hicks signed with the US, in which he confessed to supporting terrorism, he was banned from talking to the media for a year. While there is federal and South Australian legislation to prevent him from ever profiting from the sale of his story, no one seriously believes the US would re-arrest him if Hicks spoke publicly at the weekend.
It is not yet clear when and how Hicks will be freed on Saturday. He may be sent out the front gate at 10am, like other prisoners. But this is increasingly unlikely because Hicks wants to avoid media.
"He is in a frame of mind where he doesn't know if he will have an anxiety thing like he did when they whizzed him up to Holden Hill," said Terry Hicks. "His problem is he has been locked away for nearly six years in a small area then all of a sudden he walks out the front gate. This is huge. All of a sudden people are firing things at him. So we don't know what the end result would be."
The Australian Federal Police, the South Australian Government and Hicks's family and legal team will be in talks this week about his release. Mr McLeod said it was fair to say that "everything had been considered". This includes driving Hicks out of the prison under a blanket in the middle of the night, possibly a day or two early, and even from another prison where he could be transferred this week.
It had been thought Hicks would read a brief statement and allow himself to be photographed, and his family had hoped he would get it over with, but Terry Hicks said: "At this point he thinks it's in his best interests if he doesn't talk or see anyone. There may be a statement, but he won't be there. As far as I know, at this point he doesn't want to be seen, heard or whatever until further down the track. I think he just wants the time to reorientate himself."
Great care was taken in court last week to avoid describing where Hicks will live. He will go to an address that federal police have approved. Until he tells them of a change, this is where he must be every night between midnight and 6am.
Mr Hicks said his son would not be staying with him. "The media is pretty good, pretty astute. You will find him, but we are hoping for two or three days at least before they track him down."