There are many reasons that might force a kid to grow up too fast. But when it’s in conjunction with having to care for a parent, we can consider it ill-fated. Director Inon Shampanier co-wrote the script with his wife, Natalie Shampanier. They adeptly handle a story that, in lesser hands, could be over-wrought and not believable. Instead, they benefit from two excellent performances and deliver an emotional and poignant tale of mother and daughter- and mental illness.

Lili Taylor stars as Dawn, mother to straight-A high school senior Melanie, played by Stefania LaVie Owen (“Messiah”). We first meet them while on a rainy campus tour. Dawn is direct in expressing her wish that Melanie remain close to home for college, while ambitious Melanie wants to attend her late father’s alma mater, USC, on a full academic scholarship. It’s clear mother and daughter have a close relationship, but something is a bit off about Dawn, and we get our answer soon enough.

As the new neighbors are moving in, the truck backs into a tree that Dawn’s husband planted years earlier. Dawn flips out, setting off a chain of events where she is convinced the new neighbors are spying on her, tormenting her, and endangering her. Of course, there is no proof of any of this, and the further Dawn slips, the more difficult it is for Melanie to carry the burden of school, a social life, and a paranoid-delusional mother.

Michael Cyril Creighton plays the school counselor that Melanie ropes into meeting with her mother. The scene is played to an awkward comedic effect, but also exemplifies how mental illness creates a stressful environment for everyone involved. Dawn’s agitated attorney boss is played by David Rasche, and Melanie also sets up a profile for mom on an Internet dating site, with less-than-hoped-for results. During all of this, Melanie begins a relationship with a rich, alcoholic classmate named Daniel (Ian Nelson), who understandably isn’t equipped to deal with the situation either. Peyton List plays Melanie’s best friend Lacy, and Max Casella has a couple of scenes as the private investigator Dawn hires to surveil the neighbor. All in all, it’s a cluster of real-life twisted up by mental illness.

Lili Taylor is excellent, and makes sure she keeps Dawn’s actions in the believable-yet-sufferable mode. But the film really belongs to Stefanie LaVie Owen. This is a staggeringly good performance from the young actress, and she quietly conveys a strength in the face of shock and frustration, and the unfair burden she must carry. The film is a reminder that we don’t get to pick our family, and the responsibilities can feel overwhelming at times. It’s not a horror film, but rather one filled with personal horrors – and the film’s title will make sense by the end.