The police notched up nearly half a million sick days because of poor mental health last year.
Shock new figures reveal a total of 489,484 work days were lost among 31 forces across Britain.
The UK’s “worst police force”, topped the league for losing the most work days through mental health.
Cleveland Police, described as “failing” in all areas in September, saw mental health cited as the reason for 9,711 sick days – 48.5 per cent of all the force’s sick days.
Cambridgeshire Police notched up the second highest rate, with 45.5 per cent of its sick leave used for mental health reasons.
Essex Police’s rate of 39.7 per cent was third.
South Yorkshire Police had the lowest rate, at 9.7 per cent.
Police have warned cops’ mental health is suffering after years of cuts.
The Police Federation’s Ché Donald said: “Our officers are under an immense amount of pressure due to rocketing demand... Our colleagues have been left feeling mentally battered and bruised.
"Light is on the horizon with the Government pledging the creation of a Police Covenant which will go some way in recognising these concerns and addressing them accordingly.
“But chiefs and politicians need to walk the walk and not just talk the talk because our dedicated officers deserve better after years of broken promises.”
Derrick Farrell, CEO at Vita Health Group, is calling for mandatory improvements to mental health care, including training so managers can spot the signs of cops under pressure.
He said: "It’s absolutely essential that every single member of the force is given complete support.
"This should include ensuring Police leaders and senior managers have extensive mandatory mental health training so they can recognise warning signs amongst employees and that officers of every rank have a clear pathway to getting the mental health support they need.”