More than 1,500 years of school staff time in Scotland has been lost due to mental health reasons since April 2017, data suggests.
New figures from the Scottish Liberal Democrats show that 1,503 years - or 548,439 days - of absence have been taken by teachers and support staff, where mental health was cited as the reason.
Figures from 25 of the 32 local authorities showed that the number of staff days lost has risen from 139,979 in 2017-18 to 181,191 days lost in 2019-20.
And Glasgow was shown to have had the largest number of staff days lost in 2019-20 at 20,821, followed by Highland on 17,667 and Edinburgh on 13,464.
Education spokesperson Beatrice Wishart warned that teacher morale was "heading in the wrong direction".
She said: "These figures show that since 2017-18, 550,000 staff days have been lost for mental health reasons. That's 1,503 years' worth.
"The pressures caused by the SNP's top-down approach to education and the loss of valuable classroom support have been obvious for some time. It's no surprise that both teacher morale and Scotland's performance in international educational surveys are headed in the wrong direction.
"All of this was taking its toll long before the coronavirus pandemic came over the horizon.
"Since then, teachers have been thrust into the front line, dealing with conditions that no other group has been asked to tolerate. It will be no surprise if absences this year are even higher.
"Scottish Liberal Democrats will continue to call for a better pay deal for teachers, backed by an independent review of their conditions and the demands placed upon them and a new package of measures to make teaching the valued and rewarding profession that it should be."
A Scottish Government spokesman said: "Supporting the health and wellbeing of teachers and other staff is of paramount importance.
"This was true before Covid-19, but it is of crucial importance as school staff support our children and young people to recover from the effects of the coronavirus crisis.
"In September, we announced a package of support for school staff, with Barnardo's Scotland and mental health charity Place2Be offering new mental health support.
"This additional help complements the excellent practice which is already taking place to support the wellbeing of staff in schools across Scotland.
"Teachers' pay is a matter for the Scottish Negotiating Committee for Teachers. Pay discussions will commence after the festive break and the Scottish Government will play its part in these discussions."
