A longitudinal study of 1,420 children found that bullying has lasting negative effects. Both bullies and victims were at higher risk as adults for problems like depression, anxiety, substance abuse, and suicide. Victims were four times more likely to develop anxiety disorders. Bullies were four times more likely to develop antisocial personality disorder. Those who were both bullies and victims, called "bully-victims", faced the worst outcomes and were at much higher risk for panic disorder, depression, and suicidal thoughts compared to those not involved in bullying. Preventing bullying could help reduce human suffering and long-term health costs.