Relationship between the experience of being a bully/victim and mental health in preadolescence and adolescence: a cross-sectional study.

Background: Several studies have proven that the experiences of being bullied or bullying others are associated with poor mental health among adolescent youths. Our study aims to investigate the relationship between the experience of the bully/victim and mental health among preadolescents and adolescents.

Methods: Subjects were the Japanese fifth and sixth grade elementary school students (preadolescents: mean age = 11.3 years;  = 338) and junior high school students (adolescents: mean age = 13.8 years;  = 486). A self-report questionnaire was administered containing items concerning the experience of being a bully/victim and the Youth Self Report (YSR).

Results: Four groups relating to the experience of being a bully/victim were formed: "Victim Only," "Bully Only," "Victim and Bully," and "Neither." Approximately 65% of preadolescents and approximately 25% of adolescents engaged in bullying behaviors. Of these, the rate of participants in the "Bully Only" group was low, and that in the "Victim and Bully" group was high. Regarding the relationship between the experience of being a bully/victim and mental health, both preadolescents and adolescents of the "Victim Only" group had significantly higher scores on the YSR's internalizing problems compared with the "Neither" group. Moreover, both preadolescents and adolescents of the "Bully Only" group had significantly higher scores on the YSR's externalizing problems compared with the "Neither" group. Regarding the relationship between the experience of being a bully/victim and suicidal ideation for both preadolescent and adolescent girls, the relative risks of suicidal ideation were significantly higher in the "Victim and Bully" group than in the "Neither" group.

Conclusions: Preadolescents indicated a higher rate of bullying behaviors than adolescents. In both preadolescents and adolescents, different effect patterns on mental health were found for the "Victim Only," "Bully Only," and "Victim and Bully" groups. The prevention and intervention methods for mental health should be tailored according to the type of experience associated with being a bully/victim and according to the developmental stages of preadolescence or adolescence.