ABANDONED. Novel about two sisters, one with manic depression?

[Tiffany]

This novel was about two sisters--the olde a lawyer and newlywed, and the younger a mother of four children who also has bipolar/manic depressive disorder. The younger sister has an incredibly difficult time coping despite being very well off financially and having lots of help. She goes into a deep depression and ends up try to end her life, and the life of one of her children through asphyxiation, and ends up being tried for attempted murder. I really loved this book, and can't remember the name or author!

[Lobstergirl, au gratin]

When did you read it? What genre was it: literary fiction, chick lit, crime? Remember the cover? What country is it set in?

[Lobstergirl, au gratin]

No response in 2+ years. Moving to Abandoned.