Just as Hannah herself resists typical far-fetched sitcom stereotypes -- she's not model thin, she struggles with her finances and her career choices-- her OCD symptoms are presented in a way that resists the low-hanging fruit of a kooky character most of us never encounter in our day-to-day routine.
If this were school, the girls of "Girls" would be failing. But it's life, so it's even more depressing. We're already eight episodes in to Season 2, and the girls' togetherness scores have only decreased. Hannah's suffering from OCD, Marnie is desperately following Charlie around Manhattan, Shoshanna is hooking up with doormen, and Jessa is missing.