Hundreds of children with mental health problems are being treated on adult psychiatric wards, the BBC has reported.
A Freedom of Information request by the broadcaster to NHS mental health trusts in England also found many young people were being placed hundreds of miles away from home for treatment.
Figures from 51 of the 58 trusts showed that 350 under-18s have been admitted so far to adult mental health wards in 2013-2014, compared with 242 two years earlier.
They also revealed that 12 under-16s have been admitted so far in 2013-14, compared with just three in 2011-2012.
Ten trusts had sent children more than 150 miles away for care.
Sussex Partnership Foundation Trust said it had to transfer a child 275 miles away to Bury in Greater Manchester because there was no bed available nearer home.
Michael McClure, clinical director of children’s and adolescents’ mental health services at Central and North West London Foundation Trust, said doctors face this problem every day.
“Sometimes we have to make 50 to 100 phone calls around the country looking for a bed,” he told the BBC.
“They [young people] shouldn’t be shunted around into inappropriate facilities, however much the staff there try to help them,” said Dr McClure.
“It may be the first time they’ve had a breakdown. They need to stay in touch with the people they know and love, and if they’re having to move 200 or 300 miles, it’s very difficult for the family to stay in touch.”
Jacqueline Cornish, NHS England’s national clinical director for children, young people and transition to adulthood, said treating children with mental health problems in adult settings was “totally unacceptable in the majority of cases”.
NHS England is conducting a three-month “rapid review” into the situation, she told the BBC.
The Department of Health said children and young people’s mental health was a priority.