The Safdie brothers’ divisive portrait of a New York heroin addict’s deadbeat existence hews closer to Larry Clark than Trainspotting. A cast of varyingly unwashed, toothless, abrasive semi- and non-professionals scratch harsh truths from lead Arielle Holmes’ memoir of her time on the margins. As they shuffle, zombie-like, from one grating encounter to the next, you feel the Safdies shaping deathly dull flophouse downtime to make even upright citizens feel the need for a hit of something. As with actual junkies, it can be a headache, a bore or a horror show, but the directors find arresting details to illuminate aspects of this experience. A quasi-epic attempt to thread a sewing needle suggests our heroine’s desperation to restore some part of a broken life, although here, as elsewhere, Holmes is so convincingly zonked one can only wonder what’s still in her system, and in her soul. Cautiously recommended.