Girl, Misunderstood

After seeing Girl, Interrupted I came to the conclusion that many, if not most, of the patients in the hospital were misunderstood. Misunderstood by the doctors, nurses, the people who sent them there, even by their fellow patients. In the scene where each of the girls were reading their charts, Susanna described her condition with 'symptoms' what I thought to be somewhat typical for any teenage woman. With this in mind, is it right to consider her to be insane? Because she has "an instability of self-image, relationships, and mood, uncertainty about goals, impulsive in activities that are self-damaging...such as casual sex", these make her suitable for a mental institution?

I feel that these 'symptoms' should not be the criteria for someone to be considered insane. For example, because Susanna was uncertain about her goals, this qualified her for a year stay in a mental hospital. I think the real qualifying factor is the underlying reason for the 'symptoms'. What I mean is this: people should not be judged as insane by the way they react to things, but by what it is they are reacting to and because of this they are misunderstood.