CAD is caused by a narrowing of the blood vessels that supply blood and oxygen to the heart. It is the leading cause of death in the United States. Recent evidence has suggested that individuals with increased hostility levels have a higher risk of developing CAD than individuals with lower hostility levels. The autonomic nervous system (ANS), the involuntary part of the nervous system that is responsible for controlling the body's internal environment in a coordinated manner, may play a role in CAD development. High levels of hostility may elevate ANS activity and increase the release of certain hormones, which in turn may lead to hardening of the arteries and CAD. Cognitive behavioral therapy (CBT) has been effective for treating individuals with hostility. Through CBT, individuals develop coping skills to deal with their anger. This study will evaluate the effect of a CBT hostility reduction treatment program on ANS heart regulation and overall CAD risk in individuals with high levels of hostility.