I'm not sure if this counts as abuse, but I think if I feel guilt over it and I think it might be abuse... it probably is.
My freshman year roommate was a very timid and shy girl. She apologized for everything and went out of her way not to upset or offend me (not that I am easily upset or offended). Had I been educated on abuse like I am now, those would have been red flags for someone who maybe had been abused. Sure enough, one night we got drunk and she told me all about abuse she suffered as a child and teenager, and it was very clear she struggled with it every day.
I did suggest therapy -- I told her I go, and it helps me a lot -- but when she refused to go, instead of supporting her and being kind, I decided I would take it into my own hands. I would scold her whenever she apologized for something unnecessary, I would shame her when she was unable to make a decision, I would chastise her when she didn't stick up for herself or speak up when she wanted to.
I feel terrible about how I treated her. I should have been more empathetic, more kind, more willing to listen and accept her rather than try to force her to change. Now that I myself have been a victim of abuse (much different than her experience, though), I understand how it changes your behavior. I feel very guilty still for not being understanding, although we got dinner a few months ago and I apologized for being so mean to her freshman year. She was very gracious and for that I am grateful.