There are a million ways to parent these days. And at least ten books to choose from, each backing up and “certifying” that this way or that way of raising a child is the perfect way to do it. And whether parenting is instinctual or learnt is a never-ending debate, but most authorities seem to agree it’s certainly a mix of both. The line dividing instincts and learned behavior (and how trustworthy each is) is one of the more fascinating parts of observing parenting—and most assuredly a point of dissent among parenting theory enthusiasts—and director Saverio Costanzo taps into this intriguing area with equal parts sympathy and horror. With Alba Rohrwacher (I am Love, Constanzo’s The Solitude of Prime Numbers) and Adam Driver (in his first feature lead before he takes over the world when Star Wars: Episode VII comes out) propelling the film with mesmerizing and emotional performances, Hungry Hearts is sickeningly distressing and heart-stirring.

Capitalizing on the chemistry between its main characters, Hungry Hearts starts in charming romantic fashion. Driver’s Jude is abroad on a business trip and meets Rohrwacher’s Mina in rather a stressful style. Mina accidentally walks in on Jude, holed up in a restroom sick from food poisoning. She attempts to leave and finds the door has locked itself behind her. Stuck together in a most uncomfortable, and malodorous, situation they have nowhere to go but up and with an amusing meet-cute story to boot. From there, time progresses—they are together in New York City facing the possibility that Mina be transferred out of the country for work. But work-life decisions are waylaid quickly by news that Mina is pregnant. Surprised and scared, the two embrace this new development in their relationship and marry. At their quaint Coney Island wedding Jude’s mother encourages Mina to visit her any time and Mina reveals that her own mother died when she was a baby and she and her father no longer have a relationship. She practically glows with her enthusiasm to form her own new family.

Early in her pregnancy Mina shows skepticism in modern forms of pre-natal care. She rejects her doctor’s wishes that she eat more and try to gain weight for the baby’s sake, preferring to eat a strict vegan diet that doesn’t provide enough nutrients for her child. She rejects her morning sickness, believing it instead to be a sign that she needs to eat more “cleanly.” When she walks by a psychic’s business one evening, she goes in, visibly relieved to hear her child is an “Indigo” child, a New Age concept marking a person as “special” and possibly containing supernatural gifts. Throughout her pregnancy and into child-birth Mina rejects Jude’s advice and the guidance of her doctor, but despite the odds she does give birth to a relatively healthy child, albeit underweight.

Blinded to outside reason or science, Mina is totally devoted to her child and filled with the overwhelming conviction that she’s following true instinct and correctness. Rohrwacher could so easily have given Mina a psychotic edge, discrediting and demonizing her, but her love and devotion are played out with such ferocity it really does look like instinctual mothering. As Mina wastes away, following the same diet as her poor infant, she appears almost to toil for her child’s sake, as though sacrificing for him. The most obvious parallel would be to Roman Polanski’s Rosemary’s Baby. Mina’s skeletal back and sunken eyes look quite reminiscent of Mia Farrow’s slight form as her child sucked the life from her.

Constanzo also employs other horror tactics, most obviously the hovering camera—using a fish eye lens high above the characters to simultaneously make Mina look even more waif-like and also act as an evil eye of sorts looking down at the increasingly complicated scenario playing out. It’s a distracting technique, deliberately so, and marks a rather shaky transition within the film from problematic family drama to dread-inducing horror. Each of the film’s transitions, from dating to marriage, from couple to parents, and all the way up to the film’s rather unnerving (and maybe overly dramatic) ending, are rough edged. They feel off, but can’t really be considered pitfalls of the film—as the situation gets more and more complicated, the feelings each progression stirs up are meant to match the progressively frightening story. Similarly the music choices of the film feel intentional, with songs often starting at the tail end of scenes and bleeding into the next in a way that contrasts rather than unites these scenes. It all comes together to feel wrong, but its all supposed to.

While Rohrwacher elicits sympathy and terror as Mina, it’s Driver who truly grounds the film, keeping it from slipping too far into horror territory and giving it the sliver of sanity it needs. Driver perfectly depicts Jude’s manic and fractured needs as they waffle between his love for his child and instinctual desire to keep him alive, and his overwhelming love for his wife and his wish to trust her and try to make their family unit work. It’s how convincingly both Driver and Rohrwacher convey these competing “instincts” that really presents a compelling look at parenting and especially its effects on the relationship of the parents. Though obviously a dramatic and extreme version of parenting, Mina and Jude’s behaviors don’t feel too far off from what many of us know of parenting techniques out there, a spooky thing to consider.

Luckily the film doesn’t feel overtly political on the subject of parenting, instead focusing its energy on the psyches of its protagonists. Alone in a foreign country with no family of her own, Mina crafts a world that feels right for herself, and torn by the competing love of spouse and of child, Jude reacts the way he must. Constanzo has created a harrowing and hard to watch film, but the sincerity of its performances and the tantalizing and rather unexplored content it delves into, make for the sort of film that is impossible to turn away from. Sure to evoke a range of reactions from parents, couples, and singles alike, Hungry Hearts is nuanced psychological terror at its best.

Hungry Hearts is out in New York on June 5 and LA June 12.