Mental health is subjective. Having mental health or mental illness is like being Pro-American or Anti-American. Having mental health is like adhering to religious dogma (often the pseudo medical quasi religion of psychiatry) and being accepted by society for it. Having a mental illness is like being Heretical. According to psychiatrist Thomas Szasz, in the past, people manufactured witches (who where sometimes literally burned at the stake), now we create mental patients. Szasz wrote about 35 books, consider reading some of them.

http://psychclassics.yorku.ca/Szasz/myth.htm