Is Pat really bipolar?
He obviously is mentally unstable, a lot neurotic, and lacks any type of tact....but I don't see him as bipolar(going through long manic/depressive phases). Unless throughout the whole movie he's manic and the whole "silver linings" thing is a part of that. I read his diagnosis was not specified in the book...perhaps they just threw it into the movie to make it more comprehensible.
Thoughts?