What is the author's style in Girl, Interrupted by Susanna Kaysen?

Kaysen developed mental illness as a teenager and was committed for a period of approximately eighteen months after attempting suicide. She was formally diagnosed with Borderline Personality Disorder and was declared in remission at time of discharge. She clearly possesses the personal experiences necessary to authoritatively discuss the topic of mental illness. Her brief memoir is a personal examination of the nature of mental illness and is presented in the first-person, limited, point of view. In general, the memoir is presented in the past-tense; however, exceptions to both narrative constructions are commonplace. References to the second-person are frequent; for example, "You could pop into the seclusion room, shut the door, and yell for a while" (p. 46).