It wouldn't *necessarily* actively harm (at least not more than a few reckless decisions would harm non-depressed people), and "stay in your dorm room bed an entire week reading comics" wasn't necessarily less self-harming than getting blackout drunk, but I knew plenty of people who powered through a much more extroverted college depression than mine and they were not inherently more or less miserable than I was.

If LW's kid is getting out of his room to play piano and keeping up with schoolwork and stuff there's no particular reason to think he's having any trouble though.