Bipolar disorder is a serious mental illness which is characterized by extreme shifts or swings in a person’s mood. Persons with bipolar disorder may one month be active and seemingly filled with inexhaustible reserves of energy and at another time be depressed and listless. These periods of alternating high and low mood are referred to as episodes. But not every person with bipolar disorder experiences these episodes with the same frequency and intensity, so the disease is broken down into two types: bipolar I and bipolar II. Bipolar I is considered the more severe form of the condition and is defined by at least one episode of intense energy called mania coupled with repeated bouts of major depression. The manic episodes for a person with bipolar I can be so significant that sometimes hospitalization is needed. Bipolar II is defined by milder expressions of episodes of intense energy and activity that is somewhere just short of mania. These episodes are not full blown mania but still show high levels of impulsivity, activity and energy. Compared to persons with bipolar I, those with bipolar II also tend to experience more frequent periods of depression. A recent study has shown that there are other subtle differences between these two forms of disorder having to do with personality traits. The study used a standardized method known as the NEO Personality Inventory to gauge potential differences between patients living with bipolar I and bipolar II. The inventory uses 240 measures for traits like extraversion, conscientiousness, agreeableness, neuroticism, and openness. The study examined 85 persons with bipolar I and 43 with bipolar II to find out what personality differences might be relevant to diagnosis. All the subjects had demonstrated two consecutive months of emotional stability prior to the study. Participants ranged in age from 18 to 65. The results showed that persons with bipolar II demonstrated a higher degree of neuroticism, especially in areas like depression, anxiety, vulnerability and self-consciousness. At the same time, these subjects showed lower levels of extraversion and positive emotions along with lower scores for striving toward achievement and competence. Although the researchers agree that more long-term study is required, they feel that these results are helpful in going beyond measuring manic episodes in determining whether a patient is living with type I or type II bipolar disorder. The study gives preliminary evidence to show that distinct personality traits also differ between the two kinds of bipolar disorder. While these differences may seem minute to a person who does not live with bipolar disorder, for the person who does, understanding more about the condition more quickly means better, faster treatment, which in turn, means a speedier return to normalized living.