He had a medical condition that left him more or less unable to speak that was only corrected through a risky surgical procedure that could have left him permanently mute.

Being unable to communicate with other humans in person is a different level of isolation, and I definitely believe it likely contributed to him breaking entirely.

That said, the rest of the BtB series mentioned in this thread also made it pretty clear that he sucked for a long, long time before that. It just went all gas no brakes at that point.