Health experts and refugee advocacy groups fear children on Nauru could have an unusual condition seen in Sweden's refugee community.
It has been called "Sweden's mystery illness".
Over the past two decades, hundreds of young refugees and asylum seekers in the Scandinavian nation have suffered from an illness where they withdraw from the world and plunge into a coma-like state.
Effects can last for months or years.
What is resignation syndrome?
Known as resignation syndrome, or "uppgivenhetssyndrom" in Swedish, it sees children gradually stop eating, drinking, walking and talking before becoming catatonic.
In many instances, they do not respond to any stimuli and need to be tube-fed.
One Swedish study says it is typically connected to "a strenuous and lengthy migration process".
"Recovery ensues within months to years and is claimed to be dependent on the restoration of hope to the family."
Few, if any cases have been noted outside the refugee and asylum seeker community in Sweden. Until recently.
Resignation syndrome on Nauru?
For more than two weeks, a 12-year-old boy on Nauru refused food and had to be flown to Australia for treatment on Tuesday.
The Iranian refugee was kept in the International Health and Medical Services clinic where he was sustained by intravenous fluids.
His situation has been widely reported as a hunger strike, but some refugee advocacy groups believe he could have resignation syndrome.
Refugee Action Coalition spokesperson Ian Rintoul told SBS News there is a "real possibility [the boy is] suffering from resignation syndrome".
SBS News also spoke with founder and president of Doctors for Refugees, Dr Barri Phatarfod, about the 12-year-old boy's case.
"Resignation syndrome is a continuum - it is the rarely-seen progression beyond profound depression. It is rarely seen as the vast majority of cases are picked up and treated long before this develops," Dr Phatarfod said.
She said while there was not the level of expertise on Nauru to "make such an assessment accurate ... certainly, his clinical manifestations are highly consistent with resignation syndrome".
"If this occurred anywhere in Australia, it would result in urgent and immediate paediatric and psychiatric intervention," she said.
"Yet these children have remained essentially neglected on Nauru until their withdrawal from life reaches the stage where they even withdraw from taking in food and water."
SBS News contacted the Department of Home Affairs about the boy and asked if it believes there are cases of resignation syndrome among children on Nauru.
A spokesperson for the department said: "we don't comment on individual medical cases".
'All children affected'
There are around 120 children on Nauru and Dr Phatarfod said it was likely that "every single one" had "some form of mental health issues".
"It's impossible not to when they are referred to only by number ... and there is no prospect of release," she said.
Dr Phatarfod said some children have witnessed suicide attempts and experienced sexual assaults.
"We see children wetting the bed well past adolescence and children as young as three displaying inappropriately sexualised behaviour - behaviour that would only come from having this acted upon themselves."
Refugee Action Coalition's Mr Rintoul said the cases of children withdrawing is unsurprising.
"Their withdrawal from society is a reflection of their complete powerlessness and insignificance, the mirror image of their social situation; completely excluded, yet totally trapped."
"The children are socialised in an alien and hostile environment ... These children have grown up is an extremely socially deprived situation, denied education and a future".
A Swedish prescriptive
SBS News spoke with Dr Karl Sallin in Sweden, a paediatrician who has studied resignation syndrome.
Dr Sallin said it is difficult to ascertain if children on Nauru are affected by the disorder.
He said in the case of the 12-year-old boy, it depended if the hunger strike was a decision consciously made by the individual.
"They don't actively refuse or make up their minds, at least so it seems, not to eat. Rather, they enter a state of 'introvertedness' that proceeds to stupor and finally complete unresponsiveness, even to pain. They are in a coma-like state," he said.
Dr Sallin called the illness a "cultural-bound syndrome, meaning it is a specific reaction pattern that is sustained in a certain context, in this case that of Sweden".
"The particular reasons for 'why Sweden' are obscure and more research is needed," he said.
He said it was possible that Sweden had the right conditions for the condition to "thrive" and "culture-bound syndromes exhibit a contagious element and media attention may enable spread".
But, he said, all patients he knew of "recovered and do seemingly well; they go [back] to school and develop friendships and get jobs".
Director of advocacy and campaigns at the Asylum Seeker Resource Centre Jana Favero told SBS News the mental health of the Nauru children will not improve while they are on the island.
"Some of them have been there for up to five years ... They cannot recover on Nauru because Nauru is the cause of their trauma," Ms Favero said.
Her point was echoed by Dr Phatarfod, who said, "we know in Sweden that children have been in this state of resignation syndrome for several years - and that's with the best of medical and psychological care provided to them".
"Who knows how long these children in Nauru, trapped on a barren and often hostile island, will fare."
The concerns come as a coalition of more than 30 organisations demand the government get all refugee and asylum seeker children off Nauru by Universal Children's Day on 20 November.
The CEO of World Vision Claire Rogers said, "these children have been forced to see and endure things that no child should ever see".
"The clock is ticking. This harmful, secretive and dysfunctional system of indefinite detention must end," she said.
SBS News contacted the Department of Home Affairs with questions about removing children from Nauru and what kind of support services are offered on the island.
"A range of care, welfare and support arrangements are in place to provide for the needs of refugee children and young people," the spokesperson said.
"Service providers are contracted to provide age-appropriate health, education, recreational, and cultural services."
Australia's offshore policy is designed to deter people from embarking on treacherous sea journeys, with the spokesperson reiterating that "the Australian Government's position has not changed, these individuals will never come to Australia".