Anorexia Recovery & Treatment

Anorexia refers to the psy condition when people do not eat because they have a distorted body image.
But what is the name of the condition when someone does not want or cannot eat, and this is not related to his body image, i.e. has other psy reasons?
How do I find more info on non-anorexia related under eating?
Well, here is what I am trying to research: my friend separated from her bf, it was her decision, but has since lost her appetite. She is now too thin, and fully ackowledges she has to eat, but she can’t: nothing will go down, aside from some milk and cookies or a banana.
She also started having panic attacks, and that wears her out totaly, as she is so thin.
So this is what I am trying to research, how to make her eat again, what could be the reasons (is separation good enough reason?) etc.
Only I keep coming up with anorexia nervosa pages…

I need to know what the scientific study (ends in -ology, example; pathology) would the study of eating disorders like anorexia and bulimia fall under.

I also need to know what depression would fall under.

This is for a science project due tomorrow. Please help!
Thank you!