I agree with the description. Why? Because the joy people describe at going to the meetups seems out of proportion to what goes on in the meetups - unless, as the old saying goes, hunger is the best spice.

I started with the assumption that most people posting here live alone or with a small immediate family and occasional interaction with acquaintances instead of as a part of a tightly knit tribe of some dozens of people who share their values and whom they have constant social interaction with. Then thought what the probable bias for site members to belong into a mainstream society tribe-equivalents like churches, sports fan groups, gangs or political organizations was.

The "mood disorder" thing is hyperbole for "your brain would like to be in a more tribe-like social environment than it is in now", not an attempt at a clinical diagnosis.