One in eight five to 19 year-olds suffered a mental health disorder in 2017, figures show.
The NHS data, based on a survey of 9,117 children, reveals the rates of illness increased with age, affecting one in 10 by the time they finished primary school, one in seven by 16 and one in six by age 20.
Women aged between 17 and 19 are the worst affected age group, with 22.4% suffering from an emotional disorder.
One in three gay, lesbian or bisexual teenagers suffer from mental health problems, compared to one in seven heterosexuals.
The research also shows a quarter of teenagers with a mental disorder have self-harmed or tried to kill themselves, rising to almost half of 17 to 19-year-olds.
Denise Hatton, chief executive of YMCA England & Wales, told the Daily Mail that while progress has been made to normalise conversations about mental health and successive governments have made additional funding available, the figures are a wake-up call that this has not gone far enough.
Sean Duggan, chief executive of the Mental Health Network, which is part of the NHS Confederation, said it is deeply concerning to see an increasing number of young people struggling with their mental health but there is now a greater awareness of these issues among children.
“It is absolutely critical that we have the resources to give the right support to every child or young person that needs it at the earliest possible stage,” he added.