A fifth of teachers have nightmares about their job and six out of 10 wake up in the middle of the night and cannot get back to sleep because they are thinking about work, say findings from a National Union of Teachers' study of members in Nottingham called Crazy About Work. The Teacher Support Network charity said the report reflects the national picture of mental health problems suffered by the profession.
The survey also found one in three "resort to alcohol, smoking, unhealthy eating or other substances to help them cope".
John Illingworth, its author, who gave an emotional account of his own nervous breakdown at last year's NUT conference, says a third of teachers will experience mental health problems during their careers.
He blamed a new breed of autocratic headteacher, trained by the National College of School Leadership, for piling pressure on staff. He said: "They say, 'This is what we are doing and there is no use complaining about it.'"
Some heads are also under pressure. Mr Illingworth read delegates in Harrogate a letter from the wife of one head who became depressed after a critical inspection and later committed suicide.
Delegates unanimously backed Mr Illingworth's call for further research into the problem.
The former Nottingham primary head sent his study to every education minister requesting meetings to discuss it. He received a reply from Beverley Hughes, children's minister, saying she was unable to meet the union because it refused to be part of the social partnership.
Patrick Nash, Teacher Support Network chief executive, condemned the Government's response as "disgraceful" and said his database suggested 20,000 teachers suffered mental illness.
Magenta Stonestreet teaches about stress as an A-level psychology teacher but has just had to take four months off work because of the problem.
"The other day I lost it with a class," she told an NUT fringe meeting. "I kicked them out of the classroom, locked the door and sat there sobbing."
She said she was one of at least six teachers at Monkseaton high, Tyneside, who were either off with depression or were recovering from the illness.
"That is not about the school," she said. "It is teaching generally."
An NASUWT poll of 5,000 teachers showed that two thirds had suffered bullying and harassment from pupils and, in many cases, colleagues.