Adapted by co-writer/director Phil Dorling and Ron Nyswaner from a 15-minute short film, Why Stop Now is an unbearable 90-minute trip with a trio of loud, needy egotists—one whose updated scenario never feels like it needs the extra 75 minutes. Why Stop Now follows Eli (Jesse Eisenberg), a college-age piano prodigy who deeply resents his drug-addict mother, Penny (Melissa Leo), for making him take care of her and his little sister, Nicole (Emma Rayne Lyle). Unfortunately for Eli, Penny’s habit prevents him from taking a job at a Boston conservatory. Attempts to clean her up are stymied by a catch-22: Penny can’t check into rehab unless she tests positive for drug use. Wan shenanigans ensue when Penny and Eli spend a long day panicking together and working with drug dealer Sprinkles (Tracy Morgan) to score. More exhausting than it is endearing, Dorling and Nyswaner’s busy script never allows the cast to develop their characters beyond stereotypes, and the tinny dialogue brings out the worst in their worst. While Morgan seems barely invested in his part, Leo’s attempts to make Penny seem obliviously desperate only reveal how difficult it is for Leo, as a performer, to appropriately modulate her emotions. Worse still, Eli’s barely contained belligerence makes Eisenberg’s often-charming motormouth shtick unbearable. There’s no emotional core to this dramedy, just a lot of ceaselessly moving parts.