With social distancing, stay-at-home orders and remote learning during the pandemic, many caregivers allowed more screen time than usual. Teenagers’ screen time doubled during COVID, and now many caregivers and parents are afraid their kid’s screen time has gone overboard. Dr. Anna Lembke, author of “Dopamine Nation,” makes the case for how technology, with its promise of nonstop engagement and flashing lights, can be addictive.