- Video report by ITV News Correspondent Dan Rivers
The ongoing conflict in Syria has claimed the lives of hundreds of thousands of people, forced millions from their homes - and now a new report shows a mental health crisis is plaguing children trapped in the country.
The study by charity Save the Children revealed many children in the country are living in an almost constant state of fear, terrified by shelling, airstrikes and ongoing violence, with devastating psychological consequences.
Mental health experts say the results of the study show children are suffering from a condition known as "toxic stress", brought on by the extreme and ongoing violence.
Continuous toxic stress can have a life-long impact on children’s mental and physical health.
Alexandra Chen, Child Protection and Mental Health Specialist at Harvard University, said that toxic stress, if left untreated, can have a lifelong impact on children's "mental and physical health".
She said the condition can disrupt the "development of the brain and other organs" as well as an "increased risk of heart disease, substance abuse, depression and other mental health disorders into adulthood”.
Experts say the problem is at a crisis point; if the war continues much longer and the children do not receive the psychological support needed it will be much harder to repair the damage caused.
Over 450 children, adolescents and adults across Syria were interviewed for the “Invisible Wounds” study which found that half of children never or rarely feel safe at school while 40% say they don't feel safe to play outside - even right outside their home.
Zeinab, a 12-year-old at a displaced persons camp in Hassakeh, north-east Syria, told the report authors: "When the war came, all the Syrian children forgot everything they learned and now know nothing else except war.
"I feel like I’ve seen so many terrible things. I lost out on two years of school, and my brother has grown up and has hardly studied at all.
"What if I get old and I continue on this same path and I lose out on my entire future?"
The psychological impact on children has resulted in bed wetting, involuntarily urination in public, speech impediments and children losing the ability to speak altogether.
The report found other effects children are experiencing have been increased aggression and substance abuse.
A rise in self-harm and suicide attempts among children as young as 12 have also been reported.
With adults themselves highly stressed and struggling to cope, one in four children interviewed said that they rarely or never have a place to go or someone to talk to when they are scared, sad or upset.
Many doctors and medical professionals have fled the country and with the continuous fighting there is little official provision for mental health services for children.
Dr Marcia Brophy, Save the Children Senior Mental Health and Psychosocial Support Adviser for the Middle East, said: "We are failing children inside Syria, some of whom are being left to cope with harrowing experiences.
"We risk condemning a generation of children to a lifetime of mental and physical health problems – we need to ensure that children who have already lost six years of their lives to war don’t have to lose their whole future as well.”
ITV News followed the plight of the 250,000 residents of Aleppo last year, reporting on the devastation people trapped there were facing, such as the damage caused by airstrikes and shelling.
Both of these came out strongly in the charity's report as the primary cause of child mental health issues.
The report states that ultimately the only way to begin undoing the damage to the children is for the ongoing violence in Syria to stop.
Kevin Watkins, CEO of Save the Children, said: "Children are soiling themselves when they hear a loud noise. They are terrified to play outside, afraid to go to school even though they are worried their futures will be ruined without an education."
In addition to an immediate ceasefire, the charity is calling for an end to using explosive weapons in populated areas or attacks on schools and hospitals.
It is also asking for unrestricted humanitarian access to all areas to allow aid agencies to reach the most vulnerable.
The charity estimates around 2.5 million children inside Syria are at risk of developing a mental health disorder unless the fighting stops and the much-needed help is provided.