MyDepressionList

This can be objectively categorized based on whether or not a person has psychological, physical, emotional, economic, and other problems.

No, it can't. These are problems for you; for someone else, they are a test, and they gratefully accept it, believing that after death, they will go to heaven and hang out with Jesus/houris/Grevan. All you can do is ask if a person is satisfied with their life at a given moment, or not.
If you really want to add some objectivity, then you could use some special tests that show the level of certain hormones that are responsible for the feeling of pleasure/happiness, and other similar things. However, there are probably cases where these hormones are released but don't reach where they need to go, or somehow don't work as they should. So...

while social activity has no direct relation to all of this. Someone may well experience suffering due to the lack of friends, a partner, etc., but this is not applicable to every person on the planet.

I didn't write that this applies to every specific person, or that something has a direct relationship to something else. I was just feeling down and making some jokes about your funny GIFs and Sevr's posts from the chat, about how he went somewhere again and how great it was. And you guys, with your philosophy, started picking on it.