The most important feature of panic disorder is the existence of a discrete crescendo of distress that peaks very quickly and disappears quickly (DSM-IV, 1994). However, a patient will frequently erroneously say that the panic lasted hours. When a person has a panic attack they feel tremendously overwhelmed and often seek help in accident and emergency units. An estimated one in three people who present at these units with chest pains has symptoms consistent with panic disorder (Fleet et al, 1994).