Refreshingly, there are few calls to a higher power in this searing, fact-based chronicle of a horrific descent into hard drugs. Instead, in their deft adaptation of two best-selling books, writer-director Felix Van Groeningen (The Broken Circle Breakdown) and his cowriter, Luke Davies (a former heroin user who went on to pen the Oscar-nominated Lion), help remove the stigma of addiction by focusing on the neuroscience of dependency. Steve Carell plays New York Times and Rolling Stone journalist David Sheff (author of the eponymous memoir), and Timothée Chalamet is his gifted teenage son, Nic Sheff (author of his own memoir, Tweak: Growing Up on Methamphetamines), a sensitive lad whose initially casual drug use morphs into a toxic cycle of lies, guilt, recrimination, and lawlessness. The leads are superb, buoyed by Amy Ryan as Nic’s mom, Maura Tierney as his stepmother, and LisaGay Hamilton in a moving cameo as a parent whose unconditional love couldn’t save her child.