Kaysen quotes the Diagnostic and Statistical Manual of Mental Disorders definition of Borderline Personality Disorder, which was the diagnosis given to her by McLean Hospital. The symptoms of this disorder include prolonged instability, and failing to make concrete decisions about relationships, friendships, sexuality, and personal values. Other Borderline Personality traits include having intense mood swings and engaging in risky or self-harming behavior such as theft, casual sex, drug use, and self-mutilation. The definition notes that many people who are diagnosed with Borderline Personality Disorder are also diagnosed with other disorders, and generally have a cynical worldview. It also says that the symptoms associated with this disorder can greatly impair the person’s ability to function in day-to-day life.

Kaysen offers a thorough commentary on her diagnosis, which she finds subjective and problematic. The author admits that the description of Borderline Personality Disorder is “a fairly accurate picture of me at eighteen,” but questions how these traits, many of which are common in teens, could be considered a disorder (136). She points out that feeling uncertain about relationships, friendships and self-identity are common hallmarks of the adolescent experience and how much uncertainty is too much is highly subjective.