A sixteenth of the PSNI's total force took time off because off stress in 12-month period.
Some 413 officers required sick leave for stress, anxiety or depression between April 2014 and March 2015, according to figures released by the PSNI in response to a freedom of information act request.
The highest number of absences (246) recorded were because of stress. The next most frequent causes of absenteeism were anxiety (74) and depression (47).
It also emerged that 32 PSNI officers had complained of post-traumatic stress disorder, that a dozen required sick leave for post-natal health concerns, and two more for what was loosely categorised as "other mental disorders".
The PSNI did not indicate which ranks had requested the sick leave referred to, voicing concerns it could help identify individuals.
Police Federation chairman Mark Lindsay said the figures reflected what he termed the "routine of upheaval" in the service.
"Stress is a serious illness affecting far too many officers," he added.
"The figure reflects what for many officers is the routine of upheaval in the workplace.
"They have to work long hours. There are last minute changes to rosters.
"It's difficult to get time off to spend with their families, and shifts are added with little regard to the impact on officers or their families."
Mr Lindsay also blamed under-staffing within the PSNI and the ongoing threat from dissident republicans.
Just last week, there was a security alert around a police officer's car.
"The service is under-staffed which places further strain on officers who have to plug the gaps," Mr Lindsay said.
"If that's not enough, officers have to contend with oversight arrangements that are the most intense in Europe and, of course, there's the constant threat that's posed by dissident republicans whose sole purpose is to murder the men and women who serve this community.
"This level of stress signposts the need for urgent action to be taken to address real concerns about officer welfare."
Mr Lindsay urged positive intervention in the problem, saying the number who have been off work with stress was only the tip of the iceberg.
"Measures must be put in place to help those who are ill and in need of professional help," he added.
"The Police Federation has long argued for positive intervention to reduce stress.
"The headline figure is 413, but the actual figure impacted by officer stress is much greater, with families also suffering."
In a Police Federation survey carried out in October, 96% of those who took part said morale within the service was low.
PSNI Deputy Chief Constable Drew Harris has pledged that numbers will not be cut despite a tight budget.
Mr Harris warned that a cull in force numbers would carry "significant risks" and insisted that everything was being done by the organisation to protect resilience levels.
He claimed the PSNI would continue to seek to protect its operational requirement of 6,963 officers, despite facing further fiscal pressures.
But he admitted, however, that no guarantees on workforce levels could be given beyond the 2016/17 financial year.
With £13m to be axed from the main policing budget next year, police bosses are planning to scale back on the number of public events officers currently cover.
Last year, it emerged that the strength of the PSNI could drop to 6,770 by April 2016 because there is no money to replace retiring officers.
In 2013, a review found that a minimum of 7,000 officers was needed for a "resilient" force.
Hundreds of mutual aid officers had to be brought in from across the UK in July to help the PSNI to police a number of contentious parades in north and east Belfast.
PSNI Chief Constable George Hamilton warned just a few months ago that he was unhappy about officer numbers.
In a bid to improve the situation, the PSNI launched a recruitment drive last September.