One taxi driver, Muhammad Anil, said his children had seen the headlines about the suicides and asked him if he was O.K. Mr. Anil, 57, told them he was fine, though he is concerned about the more than $500,000 he owes on his medallion.

“I don’t want them to worry about me too much,” he said.

Middle-age drivers may be particularly vulnerable. The suicide rate for people between the ages of 45 and 64 has jumped in recent years, more than for other age groups, said Barbara Stanley, a psychology professor at Columbia University. Suicide is a deeply personal decision and it is difficult to know for certain the factors that drive a person to make that choice.

The drivers, Dr. Stanley said, “might have been depressed in the past or had a vulnerability to depression and you combine it with these terrible environmental stressors and that’s a recipe for disaster.”

Still, many drivers are resistant to the idea of therapy.

“They’ve driven their whole lives,” said Meera Joshi, the city’s taxi commissioner. “There’s a tremendous amount of pride involved, rightfully so. Part of our messaging is that there’s no shame to needing mental health help.”

At 70, Harbans Singh still works 12-hour shifts in his taxi to pay off his medallion debt. Mr. Singh said he was not interested in counseling, adding that he relied on his Sikh faith.

“We don’t need counseling from the T.L.C.,” he said in reference to the city’s Taxi and Limousine Commission, which oversees the industry. “I don’t trust the T.L.C.”