Depends on how seriously you take the thoughts, I think.

When I'm in a bad mood, sometimes that sort of thought arises, but usually I can distract myself and replace the mood. I just remind myself that mental states are temporary, "Get up; move forward", and I'm never really concerned about the thoughts.

Of course, they are unhealthy, no matter what. And, whatever the consequence, the emotions associated with them are rather unpleasant...