The problem is that teens are spending more and more time, not talking on the phone like they were in decades past, but Instagram-ing and snapchat-ing. These are dangerous pastimes because they give the appearance of social interaction, but they couldn’t be further away from it. The comparisons that are implicit in looking at other people’s lives online, which are often highly manicured (and misleading), is thought to be what’s so depressing about social media. “These increases in mental health issues among teens are very alarming,” Twenge said. “Teens are telling us they are struggling, and we need to take that very seriously.”