On Labor Day, a 48-year-old retired sergeant with the New York Police Department was found dead in a car on Staten Island, apparently having shot himself. The department has been shaken by a rash of suicides; this case would mark the 10th in 2019 and the eighth since June, already double the number of suicides the department experiences on average each year.

Given that the city has grown ever safer, the cause of the increase is unclear. But Police Commissioner James O’Neill has spoken honestly and compassionately about what he describes as a mental-health crisis, the crucial need for peer support among officers and the importance of erasing the stigma of seeking and receiving counseling. Several weeks ago, Terence A. Monahan, the chief of department and the highest-ranked uniformed police officer, said in a radio interview that the force was looking to hire psychologists who could be out in the field, and the department was also working to improve access to mental-health professionals through the city’s inadequate insurance system.

Little of this seemed to resonate with Patrick J. Lynch, the president of the Police Benevolent Association, the biggest police union in the world, and arguably labor’s most bellicose figurehead. In a video he posted on Twitter last month, the day after an officer killed himself in Queens, Mr. Lynch delivered his therapeutically dubious message to the union’s more than 20,000 members: “If you’re on the edge and contemplating suicide, don’t [expletive] do it, come on.’’