Inspired by one of ~alaska-is-a-husky
People assign all sorts of mental & emotional disorders to their OCs with no idea about what it means. Depression does take a back seat to partying. ADHD affects hobbies and emergencies just as severely as they affect homework. Eating disorders can have long-term effects that linger even after the disorder itself has been controlled. Obsessive-compulsives can have severe anxiety attacks if their "rules" aren't followed.
Unspecified disorders are fine, but if you're going to say it's a specific disorder, then the symptoms should be consistent.On the other hand, hypochondriacs probably shouldn't research these things too thoroughly...
As with a few of my other stamps, yes, this is something I've been guilty of in the past as well. I now have considerably fewer characters with specific disorders. Partly because I keep convincing myself I have everything I research, partly because I'm just lazy as a writer.