I wonder if temporary staff have better or worse mental health than permanent staff?

It's just a thought. I should probably go and look for some research.

I assumed they may have worse mental health because of the pressures of
lack of job security, the 'outside the circleness' and the nomadic move
from workplace to workplace could all be stressors.

But maybe the repetitiveness of permanency may not be good for some
people. The sort of "affluenza" effect or getting used to something then
wanting more effect, e.g. if all you drink is champagne then you don't
appreciate Guinness. It may lead to smaller social networks though they
may be more resilient.

Anxiety may be less in a place where a person feels comfortable. I
wonder if familiar environments lead to better outcomes in psychosis?

Depression is a complex aninmal. I would guess that it would work out
that some types of people have better mental health and outcomes doing
temporary work and others prefer permanent contracts.