Joshua James Maddox, who had learning difficulties, was found dead at his home in Persehouse Street, Walsall, by his younger sister on January 31 last year.
An inquest heard he had been threatened with a knuckleduster by one child, and was punched in the chest by another during a campaign of bullying.
His mother, Michelle Maddox, said her son had left Deansfield School in Wolverhampton to attend St Thomas More Catholic School in Willenhall because he was being picked on by other pupils. But the bullying continued at his new school, the hearing was told.
"He moved to St Thomas More Catholic School because he was being bullied at Deansfield," she said. "But when he moved to St Thomas More he had to move down a year otherwise he thought he would not pass his GCSEs. It was horrible.
"He had no help from the school and because of his mild learning difficulties he was constantly picked on by other kids. The children used to tell him to go back to his own year. They told him they didn't want him there.
"One child came at him with a knuckleduster and on another occasion he was punched in the chest."
Miss Maddox said although she spoke to the school about her son's problems she felt he was not given the support he needed until it was too late. "I spoke to the school about the bullying but they never acted on it," she told the hearing.
"The only incident they dealt with was when he was being punched in the chest. It was Christmas by the time they sorted out any extra support. By then it was too late. They offered support after too many years of us struggling and Joshua struggling."
The 15-year-old was taking medication for attention deficit hyperactivity disorder (ADHD) and suffered from autism.
Dr Dragana Radibratovic-Cvijan, a consultant histopathologist at Walsall Manor Hospital told the inquest she conducted a post-mortem examination. She said: "His family said he had been bullied at school and they had been concerned the medication he was taking for ADHD was not working. They said he was sent to bed early because he and his brother had been stealing food from the kitchen that was meant for the family's evening meal. His stepfather checked on him once during the night and he was asleep in his bunk." She added the medical cause of Joshua's death was strangulation by hanging.
Clinical psychiatrist Dr Pauline Forster told the inquest that she had written a letter to the school requesting a meeting with tutors in 2012 but had received no reply.
"Joshua had difficulties with verbal communication and found it hard to explain emotional issues," she said. "He had difficulty socialising and making friends. His ADHD was complicated and difficult to manage. We encourage children like Joshua to have extra support in school. I wrote to the school to try and arrange a meeting but they never responded. He would tell me he was happy at school, so it was difficult to help him, even though it was clear to his family he was not happy."
Dr Forster said Joshua had changed the medication he was taking for his ADHD in the weeks leading up to his death.
Asked to describe her son, Miss Maddox said: "He used to try to make us laugh but he was always in trouble. He liked drawing, street jumping and computers.
She added: "Joshua didn't know how to talk to people. He just liked to be in his own world playing on his computer."
Senior Coroner Robin Balmain adjourned the inquest for further investigations to be conducted.
Headteacher at St Thomas More Catholic School Peter Mayland said today: "Everyone at St Thomas More Catholic School is deeply saddened and shocked by the tragic death of Joshua. He was a popular boy with many friends and a bright future. Our thoughts and prayers are with his family at this time, especially those who are students at our school.
"As a school we have a 'zero tolerance' approach to bullying, which is entirely incompatible with our Christian values.
"We work hard to listen to and respond to any concerns which students or parents may have and whenever incidents of bullying are reported to staff, they are dealt with swiftly and effectively. Ofsted affirmed this in their recent report in January 2014 when they highlighted that strengths of the school are that 'students say that they feel safe in school' and that 'bullying is dealt with effectively'."
The school refused to comment on claims Joshua had been bullied and referred the Express & Star to Walsall Council who are yet to respond.