I am pathologically introverted. Which means that I believe my introversion rises to the level of disorder--making it very hard not only to summon up interpersonal desires (relationships and socializing) but also with the basics of expression (emotions and verbal/nonverbal communication).

Yes, it bothers me. I don't want to be like everyone else, but I do want to fit in better. Feeling like an outsider all the time sucks.

But I don't think introverts hold a monopoly on mental illness. I have a sister who is the complete opposite of me. She has histrionic tendencies and bipolar disorder. Maybe our personalities contribute to our malfunctions, but I don't blame my introversion for who I am. Maybe it's a symptom itself, but it's not a cause of anything. If anything, the fact that I can be content by myself makes it easier to cope. If I had to deal with loneliness on top of everything else, I would be a hot mess.