When you spent 8 hours a day, half of your conscious time, in a situation, I have a hard time it has no impact on depression and suicide. If you have a fullfilling activity for 8 hours, it's hard for me to picture the rest of the day canceling it to the point you want to kill yourself. I tend to think it's a general context, and it includes work.
But let's be honest, I haven't worked, let alone lived in Japan, so this is just uneducated gut feeling.
Some people are happier with rote, meaningless work.
I have a relative who for 40 years has done the exact same job -- he drives a large dump truck from a stone pile in a rock quarry up to the crusher, dumps his load, and repeats, endlessly.
He's had many opportunities to transfer to other positions, but he enjoys his "meaningless" work.
He's retiring soon, which is good since the company has been testing an automated truck.
