It's 1978 and Augusten Burroughs (JOSEPH CROSS) is a confused 14-year-old living with his mentally unstable mom, Deirdre (ANNETTE BENING), who wants to be famous through her poetry, and his emotionally distant father, Norman (ALEC BALDWIN) who's growing ever more tired of his wife's endless tirades. She's started seeing a psychiatrist, Dr. Finch (BRIAN COX), whose unorthodox ways don't sit well with Norman, and thus Augusten's father eventually moves out, giving up on her and his son.
When not holding poetry meetings with the like of Fern (KRISTIN CHENOWETH) who eventually becomes one of her lovers, Deirdre spends more time seeing Dr. Cox who now holds his session at home due to tax issues. Accordingly, she drags along Augusten who's shocked to see that the psychiatrist lives in a huge, but cluttered and messy home.
He also meets the doc's wife, Agnes (JILL CLAYBURGH), who enjoys snacking on dry dog food, their older daughter Hope (GWYNETH PALTROW), who's highly religious and thinks she can read her cat's mind, and her younger sister Natalie (EVAN RACHEL WOOD), a disillusioned rebel who takes a liking to Augusten. However, when the teen informs her that he's gay, she sets him up with her adoptive, 35-year-old, schizophrenic brother Neil Bookman (JOSEPH FIENNES).
As he watches his mom slip further into mental instability as well as Dr. Finch's domineering care, Augusten must deal with his new surroundings and the collection of eccentric personalities that are now entrenched into his life.