A good article on the effects of bullying is Sarah Zielinski's "Bullying's Long-Term Effects Seen in Both the Bullied and the Bully," which was written for National Geographic. David McNamee's article "What Are the Adult Health Consequences of Childhood Bullying?" which was written for Medical News Today, is also good.
In Sarah Zielinski's National Geographic article, she discusses the long-term issues with anxiety and depression that victims of bullies can experience. She also discusses professor William Copeland's Great Smoky Mountains Study about the effects of bullying on a group of students in western North Carolina. Copeland and his team found that while bullies who were once bullied themselves tended to suffer from long-term emotional and physical health problems, those who were "pure bullies" were overall emotionally and physically healthier than their peers.