Mental illness is caused by the dog-eat-dog competitive environment of the United States. I dont' see mental illness in Africa where people don't work. Or in the tribes that live around fires and their small villages.

Mental illness is triggered by stress, yes, and, yes, unemployment would be one of those things. But the amount of money received in unemployment is insufficient to cause people a lack of financial stress.

Again, every single UBI experiment where money is in short supply, has shown an increase in wellbeing and motivation.