What is it about bipolar that makes us....?

why do we get angry, moody, irritable? ever since i could remember ive been moody, irritable and sad. but recently from the age of 15 to now 17 ive been manic. and very hostile. im taken geodon and concerta because they also think im a.d.d. so can anybody help me understand bipolar and a.d.d and maybe even the medication? id be very grateful if you could help. thank you