More than 500 members of the PSNI were forced to take time off work due to stress-related illness over the last year.
Some 515 officers required sick leave for stress, anxiety or depression, and post-traumatic stress disorder in the 12 months to last April.
The figures were released by the PSNI after a Freedom of Information request.
Last Tuesday, a report by the Northern Ireland Audit Office found sick rates in the PSNI were at their highest level. Reduced officer numbers have "put a strain" on the PSNI, the report said.
Data obtained by this newspaper shows how officers' mental health has been affected.
The highest number of absences recorded in 2018/19 (484) were because of stress, anxiety and depression.
Males accounted for the higher proportion of absenteeism, with 282 men taking sick leave for stress, anxiety or depression compared to 202 females.
A further 31 PSNI officers complained of post-traumatic stress disorder with the number of males (24) absent due to PTSD over three times that of females (7).
Meanwhile, 36 female officers required sick leave for post-natal health concerns.
And 52 more were off work for what was loosely categorised as "other mental disorders" - 30 male and 22 female.
Police Federation chairman Mark Lindsay said the figures "come as no surprise".
"The daily pressures that confront our officers are excessive," he said.
Mr Lindsay also blamed under-staffing within the PSNI and urged positive intervention in the problem.
"There has been no let-up in the upheaval they endure all too regularly. This is because there are too few officers in the PSNI and to maintain a professional service, greater demands are placed on officers.
"Their days off are changed to meet demand. Home life is upset. And, of course, far too many of our men and women are seen as easy targets for assault.
"These figures show just how important it is to both increase officer numbers to provide some relief for officers and to bring in protective measures without delay."
The latest findings come after a report from the NI Audit Office warned that the rate of sick leave in the PSNI has almost doubled since 2010.
It found that average working days lost due to sickness absence increased from eight days in 2010/11 to 14 days in 2018/19.
The number of officers on recuperative and adjusted duties has more than doubled over the same period, from 6% to 13%.
In February, the PSNI launched a recruitment campaign for 600 new student officers, sparked by a commitment in the New Decade, New Approach deal, to increase officer numbers from the current 6,900 total to the 7,500 envisaged in the Patten reforms.
Chief Constable Simon Byrne has said the PSNI requires more funding to modernise the force and recruit new officers and that it will take "two to three years" to reach the 7,500 officers target.
But Mr Lindsay says it is "imperative" that police get to a position where they have the recommended peacetime total in order to reduce excessive pressures and workload on officers.
Responding to the latest figures, PSNI Deputy Chief Constable Mark Hamilton said: "Policing is, by its very nature, a high risk, demanding and challenging working environment.
"The threat from Northern Ireland-related terrorism has remained at severe since 2010 and every day police officers and staff encounter difficult and traumatic circumstances, such as attending sudden deaths, violent incidents, road traffic collisions and serious sexual assaults and can therefore experience high levels of stress, have trauma exposure or mental health difficulties, including PTSD, as a result.
"As an employer, PSNI takes its responsibility in supporting our workforce seriously."
Mr Hamilton said the PSNI has significantly invested to improve its in house Occupational Health and Wellbeing services with an expansion of the team, having seen additional medical advisers, nurses, physiotherapists and mental health professionals being appointed.
He added: "We communicate with GPs to ensure continuity of care and safety plans are in place and have developed a post-incident stress management strategy, expanding our team of post incident de-briefers and are currently training a number of individuals to roll out training throughout PSNI under the supervision of OHW.
"Our aim is to support and improve the health and well-being of all of our police officers and police staff and this will continue to be a priority for us now and in the future."