Swimming champ Thorpe in rehab for depression
Olympic swim champ Ian Thorpe, pictured in Sydney on February 3, 2011, is in rehab for depression after a mixture of painkillers and anti-depressants left him disoriented on a Sydney street - by Greg Wood
But his manager James Erskine insisted no alcohol was involved, as the swimmer's father suggested he faced months of treatment but would "come out the other side".
A "dazed" Thorpe, 31, was discovered by police attempting to get into a car near to his parents' house in the early hours of Monday and taken to hospital for assessment.
It was his second recent visit to hospital, after falling and needing shoulder surgery last week. At the time, his management denied reports that he was also being treated for depression and alcohol abuse.
Erskine told the Australian Broadcasting Corporation that the five-time Olympic gold medallist was now receiving treatment for depression, a condition he has struggled with for years.
"He'd been taking prescribed drugs, painkillers for his shoulder and he's also on prescription drugs for anti-depression... but it's obviously a mixture of it and that mixture made him disorientated because he was wandering around at 3 o'clock in the morning," he said.
Residents rang police after Thorpe tried to get into a car that he thought belonged to a friend.
"He became disorientated and he tried to get into what he thought was a friend's car, but it wasn't his friend's car at all," Erskine said.
As well as being open about his depression, Thorpe detailed a battle with alcohol in his 2012 autobiography, but Erskine said it was not a factor in Monday's incident.
"There was no alcohol involved, he hadn't been drinking or anything like that," he said.
"The hospital then suggested -- or more than suggested, I think -- that he should go into rehab for depression and that's what's happened."
Thorpe's father Ken told the Sydney Daily Telegraph he was optimistic his son would pull through.
"He is battling with his health issues at the moment and he is having a tough time," he said, reportedly choking back tears.
"But hopefully in six months' time he will be out the other side."
Thorpe is Australia's most decorated Olympian with five gold medals at the 2000 Sydney and 2004 Athens Games, with his extraordinary success attributed partly to his abnormally large feet and hands.
He became the first person to win six gold medals at one world championships, in 2001, among 11 world titles overall -- along with 10 Commonwealth Games gold medals.
But the demands of a celebrity lifestyle and grinding training saw him quit in 2006 before a comeback in 2012 in which he failed to qualify for the London Olympics.
While every major sport in Australia runs an Athlete Career and Education Programme to help prepare for life after sport, Thorpe has not been able to find a direction, dabbling in jewellery design and television while attempting a number of university courses.
Former long-time rival Grant Hackett told Fairfax Media Thorpe was naturally introverted and thrived in the team environment, which was lost when he retired.
"It's not a transition many people are ready for and it is difficult and it's hard and you've got to have good support around you, regardless if you're high profile or not, to make that transition successfully," he said.
"I think Ian's had difficulty in that, and obviously coming in and out of the sport again has probably exacerbated some of the issues that he was struggling with. My heart certainly goes out to him as one of his closest rivals but more so as a friend."
Last week, another former great Kieren Perkins urged more support for retiring sportspeople, saying he had also struggled to adjust.