Well germany has this thing called "bürgergeld" aka citizen money, it covers rent, healthcare + about 500euros for food and stuff.
Once a year u get hussled by the agency that pays it to 'get a job or provide reason why u cant'.
And well one reason can be, that u have mental problems. In fact not wanting to work can be considered a mental problem by some.
Just treat the thing as a very low universal basic income, with the catch that u only get it if u become 'sick' by societys definition.