Partly but also indulging in a mental illness is costly for the body so if you have other stresses to deal with the brains has to choose one or the other.

Sometimes this doesn't last which is why stressed people can suddenly seem to have a breakdown out of nowhere (often when things are actually easing up).

https://saidit.net/s/science/comments/8xlr/this_scientist_busts_myths_about_how_humans_burn/