I read the book The Bell Jar when I was 17 a couple years ago, and enjoyed it even though I didn't fully understand it. I understand it better just from the experiences I've had since then, putting myself in the context of my memories of reading it. I had heard about the movie version and that it wasn't a satisfying adaptation, and after seeing it I only half agree with that assessment of it.
Certainly, it had flaws, most notably it's continued attempts to identify Esther Greenwood as Sylvia Plath directly, even having Marilyn Hassett read narration that took excerpts directly from some of Plath's most famous poems, including "Daddy," "Lady Lazarus," and "Mad Girl's Love Song." While it's true that Plath based the book upon herself and her experiences, the book stands alone as a work of it's own. We don't need to know anything about Plath to appreciate it, and that's how the movie should have presented it. By connecting it directly to Plath, they sensationalize her and her death, and indeed the whole movie is guilty of oversensationalizing.
I'm going from memory, but I don't remember the novel's Esther as going quite so crazy as Hassett's character does in this film. I don't remember her writing "gone to see daddy, good bye" dramatically with lipstick on the mirror, and I don't remember her writing a note which implied Esther had dissociative personality disorder. The screenwriters didn't seem to know what exactly Esther's problem was, so they inserted that ridiculous and inconsistent bit, as well as other dialogue that implied that Esther was schizophrenic, which she was not.
However, despite the movie's flaws, it creates the atmosphere well. Hassett turns in a believable and talented, if sometimes over-the-top performance as Esther, a brilliant university student in 1953, torn between following her dream of being a poet and becoming a traditional housewife, as girls were expected and expected themselves to become in the 50's. She is treated as an object by men, critisized by bitter, self-rightous women for her intelligence, and her mother is in denial that her daughter is cracking under the pressure placed upon her.
The other performances are excellent mostly, except for Julie Harris as Esther's mother who seems a little too weak and flaky. Part of the blame lies with the screenwriters, who don't give her enough screen time to develop her character. Barbara Barrie is convincing as the bitter magazine editor who urges Esther harshly and forcefully to update her tastes in novelists and write from the point of view of the average college student.
Donna Mitchell is powerful as Esther's good friend who is spiraling downward at the same time as she. Although they gleefully discuss the best methods of self-destruction in a bar, neither of them realizes that the other one is drowning at the same time as she. Virtually every scene with Mitchell in it is haunting, and the lesbian overtones are convincingly subtle and not overstated. I don't think the extra scene where she kills herself was necessary, but it was still effective.
Finally, Mary Louise Weller is convincing in a small but important role as the stunning southern belle who befriends Esther but does not connect with her, and saves herself from Esther's problems by allowing herself to be pigeonholed into the same category as all the other young girls of the 50's, abandoning her dreams.
Overall, the insertion of Plath's poetry borders on being insulting to her, and any attempt to translate her ingenious work will inevitably be imperfect and flawed, but this movie offers a powerful, moving effort and is a notable portrayal of a complex, brilliant girl's descent into madness and depression and her turbulent recovery.