Is meditation, at least meditation done right, good for mental distress, even that brought about by madness?

Is meditation, at least meditation done right, good for mental distress, even that brought about by madness? On the one hand, some buddhist meditation teachers do focus on relaxation and mindfulness as therapy is in vogue. On the other hand, there is e.g. zen sickness, and it may not be obvious that even equanamity is actually long term stabalizing for states of distress. I'm especially interested in zazen in general.