Sibling bullying in early adolescence may worsen later mental health

Individuals who were bullied by their siblings in early adolescence had increased risk for poor mental health later in adolescence, according to a prospective longitudinal study in Journal of Youth and Adolescence.

“While sibling bullying has previously been linked to poor mental health outcomes, it was not known whether there is a relationship between the persistence of sibling bullying and the severity of mental health outcome in the longer term,” Umar Toseeb, PhD, of the department of education at the University of York in the U.K., said in a press release. “In the first study of its kind, we comprehensively investigated a whole range of mental health outcomes, which included measures of both positive (eg, wellbeing and self-esteem) and negative (eg, symptoms of psychological distress) mental health.

“Of particular note was the finding that even those who bullied their siblings, but weren’t bullied themselves (ie, the bullies), had poorer mental health outcomes years later,” Toseeb added.

Toseeb and co-author Dieter Wolke, PhD, of the department of psychology at the University of Warwick in the U.K., analyzed data from 17,157 youth (48% girls), with a focus on early (age 11 years), middle (age 14 years) and late (age 17 years) adolescence. Participant data were drawn from the UK-based Millennium Cohort Study, which began in the early 2000s and included young people’s completion of questionnaires related to sibling bullying at ages 11 and 14 years, as well as questionnaires about their mental health and wellbeing at age 17 years. Further, parents completed questionnaires about their child’s mental health at ages 11, 14 and 17 years.

Results showed an association between bullying and poorer mental health outcomes in late adolescence, regardless of whether the individual was bullied or was the bully. Severity of mental health outcomes in late adolescence increased as the frequency of bullying victimization increased between early and middle adolescence. Bullying in early adolescence affected the developmental trajectories of externalizing problems.

“If replicated using causal methods, these results suggest that sibling bullying in early adolescence has a long-term effect on both positive and negative mental health in late adolescence,” Toseeb and Wolke wrote in the study. “Prevention and clinical interventions aimed at reducing mental health difficulties and promoting positive mental health during late adolescence are likely to benefit from reducing sibling bullying in early adolescence.”

Reference:

Sibling bullying associated with poor mental health outcomes years later, new study finds. https://www.eurekalert.org/news-releases/929741. Published Sept. 29, 2021. Accessed Oct. 7, 2021.