Can you drop out of school in year 11 at age 15?
As I understand it in the UK, the child would need to be age 16 before they could leave school. Until that time, the school system is required to provide him with an education. If the child cannot be in a standard school, an alternative school must be provided for him. That could be an actual alternative school designed for students with emotional disabilities, or it could be a homeschooling program. But no, the kid can’t just be out of school at that age.