I sometimes worry that people will think I'm making it up to use as some kind of excuse for being unproductive.

This is one of the reasons I mention my mental illnesses to a lot of people willy-nilly: I figure it helps if they learn about it in a case where it's not actively causing any problems they need to care about.

I tend to dislike attention (with some exception via the internet), and people who are acquainted with me tend to figure this out pretty fast. So I'm not too worried about people thinking my motivation is attention. If they did make that accusation, it'd be quite the fit of absurdity on their part.