Girls on the adult sexual swings
On top of the world in the morning, depressed over lunch time and angry in the evening - teenagers have a reputation for mood swings. Any rapid fluctuation in hormones is usually accompanied by irritability, recklessness, aggression and depression. In early puberty, teenagers are experiencing very rapid rises in the level of sex hormones. So mood swings at this early stage could be caused by hormones, although there is very little evidence to prove it.