Bringing Ashley Home(2011)

When her wild younger sister Ashley, who suffers from bipolar disorder and drug addiction, goes missing, Libba Phillips pours all her time and energy into finding Ashley and bringing her home. As the years go by, Libba refuses to give up hope, and, at the expense of her marriage and career, Libba finds her calling in life: creating a much-needed resource center for other families whose missing loved ones have fallen through the cracks.

Official site