I have been feeling extremes of happiness/sadness since my 5th year in high school (grade 11, I am currently 1st year university), and it seems to be over very minor things, which I can't really understand. Someone will give me a pen, and I'll be happy all day, really cheerful and up for anything, but minor annoyances will send me into a black mood, and I'll just sit, downcast, in my room all night. I no longer drink alcohol as a result of this (apart from the fact I don't like it), as it seemed to enhance my moods to unpleasant levels.