What is the meaning of the title of Joan Didion's book The White Album?

"The White Album" is the colloquial name given to the ninth studio album by The Beatles, called simply The Beatles. The album got its alternative name from its plain white sleeve. It was released in 1968, the same year in which Joan Didion's collection of essays of the same name begins.
The title essay of the collection details the author's decline in mental health during a time of great social upheaval in the United States. Didion starts off by telling us how, during this tumultuous era, she started to doubt the premises of all the stories she'd ever told herself—stories which, as she says in the essay's famous opening line, we tell ourselves in order to live.
The implication is that all the old certainties are being undermined, not just in the nation at large but in Didion's personal life too. Metaphorically speaking, this has left a huge void in the author's life—a large gap previously occupied by unreliable narratives which no longer make any sense. In that sense, her fraught, troubled existence has become a white album, a blank space on which she needs to write new stories.