Syrian children and their mothers form a circle during a group therapy session in Beirut, Lebanon on September 18, 2014. (Hasan Shaaban)

After Amira’s two uncles were killed in the siege of the Syrian city of Qusayr, she lost the ability to walk.

The 5-year-old had watched an uncle bleed to death, seen her home shattered by shells, had her arm struck by burning shrapnel. The psychological toll was too much and she stopped eating. Her muscles atrophied and her legs no longer were able to bear her meager weight.

“She saw a lot,” said Amira’s mother, who asked that her name and that of their family be withheld to freely discuss her daughter’s psychological condition.

After they fled to Lebanon, Amira’s mother would carry her daughter to schools where she met the staff members of a local non-governmental organization, Beyond Association, who arranged for Amira to get psychological care and treatment for her malnourishment. A month and a half after receiving medication and starting school, she began to walk again.

Amira’s case offers a glimpse into a devastating mental-health crisis that is taking hold among Syria’s refugee children, many of whom fled destruction at home into neighboring Lebanon, only to suffer the trauma of displacement — as well as exploitation, communal tensions and domestic violence.

The stress has left many with mental illnesses that include anxiety disorders, depression, post-traumatic stress disorder and developmental problems. Over half a million children have fled to Lebanon and four out of five of them are out of school. More than a million Syrian children in total have become refugees in Lebanon and in other countries.

The crisis is exacerbated by a lack of funding, awareness and infrastructure for mental-health care in Lebanon and growing tensions with local communities as the Syrian war continues to bleed across the border, aid workers say.

“You are destroying a people beyond the destruction caused by chemical weapons,” said Bassem al-Faris, a Syrian doctor who fled to Lebanon late last year and now lives and works in Arsal, a border town that has endured a massive refugee influx and briefly was taken over in August by militants loyal to the Islamic State and the al-Qaeda affiliate in Syria, Jabhat al-Nusra.

There are more than 1.1 million registered Syrian refugees — children and adults — in Lebanon, a country of 4 million. Nearly half of them are younger than 17.

Lebanon does not have formal refugee camps like Jordan and Turkey. Many of the refugees live in informal tent settlements or among poor communities, competing for jobs and stretching Lebanon’s infrastructure to the breaking point.

Refugees also have borne some of the blame for recent attacks here by militants who have beheaded two Lebanese soldiers and killed another held in captivity after the Arsal fighting. Some of the refugees’ tents have been burned.

“You can safely assume that the majority of the population coming from Syria have some form of distress,” said Anthony MacDonald, the chief of child protection at UNICEF in Lebanon.

MacDonald said that children and adolescents experience a “re-trauma” when they arrive in Lebanon as a result of poverty, living conditions, bouts of violence and a lack of schooling that adds to tensions at home.

A survey of 1,100 Syrian youth conducted by Save the Children and published earlier this year found that 41 percent of Syrians in Lebanon between the ages of  15 and 24 have contemplated suicide. The figure is more than 50 percent for women in the same age group.

Psychologists and doctors who work with Syrian children here report symptoms of phobia, hysteria, night terrors and regression in development through bed-wetting.

Some are still in a “survivalist” mode and are likely to exhibit symptoms later on in life, when the crisis subsides, medical professionals say.

“The sad thing is the legacy of early childhood trauma is really lasting,” said Alaa Hijazi, a psychologist at the American University of Beirut who worked with American war veterans and Iraqi refugees who survived torture. “The framework through which people view the world shatters for a lot of people after trauma.”

Refugees and aid workers say donors focus on providing immediate shelter and food assistance while neglecting mental support.

Most aid organizations here provide what they describe as “psychosocial support” for youth who have been displaced from Syria, including activities and awareness programs aimed at highlighting issues of abuse and early marriage and teaching parents how to positively discipline their children. They offer accelerated learning programs, communal activities involving refugees and Lebanese families hosting them, and drama and art therapy.

They also have set up “child-friendly spaces” aimed at getting the children to relax and express themselves. The walls are adorned with artwork by Syrian children, and young aid workers organize play activities.

Children gather in little circles to tell their stories of how they fled Syria. At a recent gathering in a “child-friendly” space run by War Child Holland, children told stories of fleeing the shelling of their homes and of parents being maimed by shrapnel.

Two 14-year-olds, twins from the village of Quneitra on the border with Israel, barely held back tears as they described their mother slowly dying from lack of medicine during a siege of the town. They blamed themselves for not insisting that she be evacuated earlier before the fighting reached their town.

The refu­gee crisis often leads to worse problems because the distress facing parents leads to tensions at home and an increase in domestic violence against children.

“This conflict is resulting in more problems, more delinquency, crimes, rape, all these kinds of crimes, and there is not enough funding to protect these children,” said Nadine Abdul Sater, the child protection coordinator at War Child in Lebanon.

But most aid organizations lack the expertise and resources to provide one-on-one therapy and treatment to children who witnessed brutality and are suffering from distress in Lebanon, and have to refer them to specialized personnel, officials say.

And mental-health care is prohibitively expensive for the refugees who need it.

“There is no mental-health infrastructure in Lebanon,” said Zeina Hassan, the mental-health technical manager at International Medical Corps, one of the few aid groups that provides psychiatric and psychotherapist support to refugees in Lebanon.

A lack of “mental-health literacy” among aid workers and the lack of specialized mental care mean that developmental disorders go untreated.

“It’s just a very heartbreaking situation because it’s almost a lost generation, the children not in school and children with trauma,” said Nathaly Gattas, an area manager with International Medical Corps who has worked with trauma victims in Lebanon. “Everything should be a safe space for children, but unfortunately nothing is.”