Amy Koppelman directs this movie, which she has adapted from her 2003 novel: a painful, intimate, sincerely intended study of a young woman’s postnatal depression. Amanda Seyfried plays Julie, a children’s author who had a self-harming episode while she was looking after her infant son and after the birth of her second child is reluctant to take antidepressants. The tone is unsubtly set when Julie’s psychiatrist, played by Paul Giamatti, quotes Sylvia Plath’s poem Balloons. Was that a well-chosen author to invoke in the circumstances?

Finn Wittrock plays Julie’s too-good-to-be-true dreamboat of a partner Ethan and Amy Irving has a cameo as Julie’s mother, separated from Julie’s father – whose own history of mental illness is supposed be a contributory factor, though the coy, blurry Super-8 memory flashback-sequences don’t give any clear hint of how exactly his disorder manifested itself. At one stage, Ethan complains that he is walking on eggshells around Julie. So is the movie. In between her first and second pregnancy, Julie is nervous and upset at the idea of moving out of their apartment to a lovely house in the country, an issue which takes the film a little close to #FirstWorldProblems territory.

The upsetting main events take place off camera, which is arguably the most responsible way to approach the subject. (News media are bound by rules on this subject, much more strictly than movies.) But I found something a little avoidant here; the film floats in a haze of ethereal lite-tragedy towards its end point, which the drama tactfully – but ingeniously – leapfrogs with a flashforward taking us to a point 20 years further on, when Julie’s daughter has a baby of her own. The film needed less sensitive good taste and more explicit storytelling passion.

• A Mouthful of Air is released on 14 February on digital platforms.