I believe in Mumkey's depression. I'm skeptical about pretty much everything else he says cos he's always seemed disingenuous. When someone makes fun of themselves as much as Mumkey does, you have to wonder about the state of their self-esteem. Someone without self-esteem tends to have weak values, and someone with weak values is likely to be impulsive and generally erratic, pissing a lot of their associations off in the process. Normally people would at least fake a certain level of consideration to remain in good standing with others, but Mumkey appears to have difficulty doing even that much. That's why the depression is believable, among other reasons.
I don't watch Mumkey's content cos it seems shit, but I've been exposed to him tangentially in a lot of ways, so this is my retarded take.