Interesting thread. I am a fairly normal guy. Successful at work, social, married with kids and generally happy, but running certainly plays a role in that happiness. I consider it like a glue. I ran in college and most of my friends and teammates who were "normal" have pretty much strayed from running since their time as competitive athletes. They have gone on to other things such as work or golf or whatever... My more manic or "interesting" teammates have doubled down on running and seem to have gotten even more eccentric over the years (I am 37).
I need to run to stay normal. I think I would have severe stress issues if I could not run. I tend to train alone, and it gives me energy. I am not an introverted person, but I definitely have traits such as the desire to be alone while I "gather energy." I am more rested after a 15-miler by myself than sitting and watching an NFL game with friends. So whether that is a disorder or not is up to someone else.
The only other thing I will say is that most of the post-collegiate runners I have met are odd balls. I don't experience the same level of oddness with other hobbies such as golf or music or beer, etc. Even the guys in my masters swim program are all pretty normal. Most of the runners I know drive old beaters and live alone, but at the same time are super successful prosecutors or surgeons. It sounds like a cliche but I have always noticed that it is true.
But embrace the oddness and if running makes you happy, great!