I think this is a new genre that they're all sort of working their way through it and haven't got all the kinks worked out yet but it's a genre that works for me.

Really Surprised!

This movie was so-so. It had it's moments, but wasn't the greatest.

One of the film's great tricks is that, for a time, you think it will go down a rabbit hole of unrealistic glorification.

++ POSSIBLE SPOILER ++ I am only giving this a 4 because they have got the mental illnesses wrong, first it is not called ' a borderline personality' because it is an illness in itself, we are not nearly Ill, the mental health professionals prefer to call it Emotional Intensity Disorder. The other point I want to make is that the vast majority of us are not murderers, we are far more a danger to ourselves. How are we all supposed to fight the stigma of all mental illness if the movie makers, the press etc keep giving out the wrong information, like branding all of us as killers. I find this all very sad as I struggle everyday with borderline personality disorder.

Shelley Gillen, the writer of A Sister's Nightmare, also wrote A Mother's Nightmare and A Daughter's Nightmare. A Sister's Nightmare is probably the worst of these three. It is about a pair of sisters, one is insane and just came out of a mental hospital, and the relatively sane for a Lifetime movie. The "twist" ending was not much of a surprise for me being that I guessed it half way through the movie. The acting in the movie was decent. The editing was as good as any other Lifetime movie. Overall, if you like Lifetime movies this is an average one. I recommend A Daughter's Nightmare or A Mother's Nightmare instead of this.

It's so great to see the lovely Kelly Rutherford of Gossip Girl stretch her dramatic acting abilities as a police officer. You might not think it but she can play both the high society matron and a cop just as well. Her fiancé is played by her Gossip Girl co star Matthew Settle. They always work well together. Her sister who is released from a mental institution after a long confinement and comes to stay with her. She is played by a regular of lifetime movies the versatile Natasha Henstridge of Species fame. With 3 A list for TV actors it's got to be better than the run of the mill lifetime thriller. It's entertaining enough and not as obvious as you would think and remains plausible. Picturesque coastal town for a filming location. Things don't get too outrageous or unbelievable. Worth a watch.

During 15 years in the Oregon State Psychiatric Hospital, we see committed Natasha Henstridge (as Cassidy "Cass" Rydert) receiving shock treatment, drawing on her arms and acting giddy. Finally considered well enough to be released, Ms. Henstridge shows up unexpectedly at the home of younger sister Kelly Rutherford (as Jane Rydert). A visibly more stable police officer, Ms. Rutherford is raising "aqua phobic" 15-year-old daughter Peyton List (as Emily) and planning to marry handsome live-in fiancé Matthew Settle (as Phil Martin). The living arrangement gets tense, interesting, silly and predictable.**** A Sister's Nightmare (9/7/13) Vic Sarin ~ Kelly Rutherford, Natasha Henstridge, Peyton List, Matthew Settle