By Dr. Brian McDonough, Medical Editor
PHILADELPHIA (CBS) - We call them personality disorders: and to our best estimate nine percent of the population has a personality disorder.
Traits of people with personality disorders include aggressive behavior, anger and being manipulative. Classic clinical examples are bipolar disorder and paranoia.
Physicians group the wide variety of disorders into clusters. The interesting thing is that most of us have some of these traits at least to some degree because each personality issue has a normal and an extreme side to it. Take anger for example. Most of us get angry at one point or another and it is usually due to the result of some event that causes us to have the emotion.
A good dose of anger with limits on an emotional outburst is reasonable and healthy. The person with the personality disorder may get angry for little or no reason and have a violent outburst.
Another example — many of us are a bit obsessive compulsive about certain things but those with a personality disorder require treatment. It all comes down to a matter of degree.