Teachers are increasingly facing mental health problems due to pressures in their working life, a survey suggests.
A new poll reveals that over a third (38%) of school and college staff report a rise in mental health issues among their colleagues over the last two years.
And over half (55%) say that their job has had a negative effect on their mental health.
The Association of Teachers and Lecturers (ATL), which conducted the poll, are due to debate the topic at their annual conference in Manchester this week.
A resolution has been put forward calling on the union to establish a dedicated working group to investigate the issue and specifically to look at the impact of performance management systems on those with mental health problems or hidden disabilities.
The survey, which questioned over 900 school and college staff, found of those who admitted they believe their job has a negative impact on their mental health (55%), 80% said they are stressed, 70% said they are left feeling exhausted by their work and two thirds (66%) said it disturbs their sleep.
ATL warned that a stigma attached to mental health issues means that many people are afraid to tell their employers if they are suffering - the poll found that 68% of those dealing with a mental health problem chose to keep it a secret from bosses, compared to 38% of those who kept a physical health issue to themselves.
ATL general secretary Dr Mary Bousted said she was shocked that many people had reported a rise in mental health issues.
But she added: "Teachers, lecturers, support staff and heads are now so over-worked that it comes as no surprise that so many in the education profession suffer from stress, depression and other mental health issues."
Dr Bousted added: "Those working in education need to be supported better, with schools and colleges making adjustments to their jobs and working conditions where necessary."
:: The poll questioned 925 education staff working in state and private schools and colleges in England, Wales and Northern Ireland last month.
A Department for Education spokeswoman said: "We know that the vast majority of teachers and school leaders are hard-working and dedicated professionals, and statistics show that teaching has never been more attractive, more popular or more rewarding.
"A record number of top graduates are now applying to become teachers and vacancy rates are at their lowest since 2005.
"We are giving teachers more freedoms than ever and cutting unnecessary paperwork and bureaucracy.
"We trust the professionalism of our headteachers to work with their staff to ensure they receive the support they need and to see that any issues are addressed."