Bullying is a form of youth violence. CENTRE FOR DISEASE CONTROL (CDC) defines bullying as any unwanted aggressive behavior(s) by another youth or group of youths who are not siblings or current dating partners that involves an observed or perceived power imbalance and is repeated multiple times or is highly likely to be repeated. Bullying may inflict harm or distress on the targeted youth including physical, psychological, social, or educational harm.
Bullying can include aggression that is physical (hitting, tripping), verbal (name calling, teasing), or relational/ social (spreading rumors, leaving out of group). A young person can be a perpetrator, a victim, or both (also known as “bully/victim”).
Bullying can also occur through technology and is called electronic aggression or cyber-bullying. Electronic aggression is bullying that occurs through e-mail, a chat room, instant messaging, a website, text messaging, or videos or pictures posted on websites or sent through cell phones.
HOW DOES BULLYING AFFECT HEALTH
Bullying can result in physical injury, social and emotional distress, and even death. Victimized youth are at increased risk for depression, anxiety, sleep difficulties, and poor school adjustment. Youth who bully others are at increased risk for substance use, academic problems, and violence later in adolescence and adulthood.5 Compared to youth who only bully, or who are only victims, bully-victims suffer the most serious consequences and are at greater risk for both mental health and behavior problems.
WHO IS AT RISK FOR BULLYING
Different factors can increase a youth’s risk of engaging in or experiencing bullying. However, the presence of these factors does not always mean that a young person will bully others or be bullied. Some of the factors associated with a higher likelihood of engaging in bullying behavior include: • Externalizing problems, such as defiant and disruptive behavior • Harsh parenting by caregivers • Attitudes accepting of violence Some of the factors associated with a higher likelihood of victimization include: • Poor peer relationships • Low self-esteem • Perceived by peers as different or quiet
HOW CAN WE PREVENT BULLYING
The ultimate goal is to stop bullying before it starts. Research on preventing and addressing bullying is still developing. School-based bullying prevention programs are widely implemented, but infrequently evaluated. Based on a review of the limited research on school based bullying prevention, the following program elements are promising:
• Improving supervision of students
• Using school rules and behavior management techniques in the classroom and throughout the school to detect and address bullying by providing consequences for bullying
• Having a whole school anti-bullying policy, and enforcing that policy consistently • Promoting cooperation among different professionals and between school staff and parents.
 Gladden RM, Vivolo-Kantor AM, Hamburger ME, Lumpkin CD. Bullying surveillance among youths: Uniform definitions for public health and recommended data elements, Version 1.0. Atlanta, GA; National Center for Injury Prevention and Control, Centers for Disease Control and Prevention and U.S. Department of Education; 2013. Available from http://www.cdc. gov/violenceprevention/pdf/bullying-definitions-final-a.pdf.
 David-Ferdon C, Hertz MF. Electronic media and youth violence: A CDC issue brief for researchers. Atlanta, GA: Centers for Disease Control and Prevention; 2009. Available from http://www.cdc.gov/ViolencePrevention/pdf/Electronic_Aggression_Researcher_Brief-a.pdf.
 Haynie DL, Nansel T, Eitel P, et al. Bullies, victims, and bully/victims: Distinct groups of at-risk youth. The Journal of Early Adolescence. 2011;21(1):29-49.
 Marini ZA, Dane AV, Bosacki SL, Cura YLC. Direct and indirect bully‐victims: differential psychosocial risk factors associated with adolescents involved inbullying and victimization. Aggressive Behavior. 2006;32(6):551-569.