Those who parent or counsel children with emotional troubles recognize how crude our current set of diagnostic categories are at the present time. Kids labeled ADHD, Bi-polar, and ODD all share similar symptoms. They all can be impulsive, easily angered, hyperactive, grandiose, irritable, etc. But a friend of mine sent me some literature from researchers at Johns Hopkins where they are beginning to distinguish differences between some of these children. They present information on a diagnosis they call “Severe Mood Dysregulation” where the presentation of chronic irritability differs from the episodic forms found in Bi-polar Disorder.
Check out these two links for more details if you are interested: http://www.medpagetoday.com/Pediatrics/ADHD-ADD/tb/4978