If you are talking about unhealthy enough to create injurious situations I think that differs by the situation and stimulus present. I don't think there is a single uniform answer. Also, it really helps if there are people around to watch for dramatic shifts in behavior before it becomes self-destructive.

It is important to note that many people may silently suffer from exceedingly minor and undiagnosed mental health defects that they may not be aware of. When you are around people long enough these qualities become more observable. In my experience it takes as little as 2 to 3 months of observation to really identify it with some amount of fine precision and learn to your own communication skills to compensate for the identified personality qualities.

I have a professional mental health counselor in my family who insists as much as 40% of the population could benefit from some minor amount of behavior altering medication. I haven't observed numbers that high from deployment environments, but I have observed a higher number of individuals fitting this criteria than you might think.

lol, that's what the pharmaceutical companies want us to believe. a lot of those medicines are based on inconclusive research and wrong assumptions. unless you're taking antipsychotics, stimulants, benzos, or a few other families of drugs, your crazy pills are probably based on bunk science.