Jill Clough, a former private-school head, moved to the state sector saying she wanted to help "redeem a school from what seemed to be inescapable failure". But in less than two years she was diagnosed with acute exhaustion brought on by unreasonable workload.
"I left the school at about 8 pm and drove home like an automaton," she said.
"Everything ached. I thought, 'I've stopped, I've just stopped.'
"I went to my doctor for a routine appointment. The doctor was new to me.
We went through the usual routine. Ten minutes later, I was on my way out of the surgery in a state of shock. 'I am sending you home for four weeks in the first instance,' he said. 'You don't need any medication other than rest.' I felt I was betraying the students for whom I wanted so much to make a difference. But the atmosphere of disbelief was now exactly what it had been when I first arrived.
"I did not know how to find the energy to start again. I had ignored the warnings of family and friends for the past several months, although I saw their distress. Now there was no choice. 'You are suffering from grief,'
the doctor said. 'These are the signs of mourning.'
"Although I love what I do now, everything has changed.
"Someone said to me a few months ago, 'I always wondered if you were arrogant or naive - I think you were naive, probably.'
"I don't think so. I had just decided to try to put my energy where my ideals were - alwaysa risk."