After two decades of radically changing the way we interact with others, social media may be facing a turning point, as experts study whether excessive use may have a detrimental impact on youth mental health. For some children, relentless exposure to social media may be one contributing factor for what many experts, including the , say is a public health crisis. "Our children have become unknowing participants in a decades-long experiment," Surgeon General Vivek Murthy told ABC News in a statement.