This report from the American Psychological Association looks at psychologist Howard Kassinove's research into the therapeutic approaches that are most helpful in dealing with problem anger, including relaxation, cognitive therapy and skill development.
Kassinove's study found that people with high 'trait anger' have anger reactions that are more frequent, intense and enduring. They also tend to report more physical aggression, negative verbal responses, drug use and negative consequences of their anger. In general, their anger negatively effects their relationships, their health and their jobs. Such anger that "disrupts or interferes with sense of self or normal routines" could warrant therapy, says Colorado State University psychologist Jerry Deffenbacher, PhD."