American college students are hooked on cellphones, social media and the Internet and showing symptoms similar to drug and alcohol addictions, according to a new study. Researchers at the University of Maryland who asked 200 students to give up all media for one full day found that after 24 hours many showed signs of withdrawal, craving and anxiety along with an inability to function well without their media and social links. Susan Moeller, the study’s project director and a journalism professor at the university, said many students wrote about how they hated losing their media connections, which some equated to going without friends and family. Moeller said students complained most about their need to use text messages, instant messages, e-mail and Facebook. Few students reported watching TV news or reading a newspaper. Students in the Maryland study also showed no loyalty to news programs, a news personality or news platform. They maintained a casual relationship to news brands, and rarely distinguished between news and general information.