Bullying by a brother or sister in childhood can have lasting effects, threatening mental health in the teen years, new British research suggests.
Researchers found that mental health was affected whether one was the bully or the victim.
"Of particular note was the finding that even those who bullied their siblings, but weren't bullied themselves [i.e. the bullies] had poorer mental health outcomes years later," said lead author Umar Toseeb, from the University of York.
Toseeb and his colleagues analyzed data for 17,000 teens to determine the impact of sibling bullying.
Participants were part of the U.K.-based Millennium Cohort Study started in the early 2000s. While young people completed questionnaires about sibling bullying at ages 11 and 14 and on their own mental health at age 17, their parents also answered questions about their child's mental health at those ages.
The research team found that as the frequency of bullying increased in early to middle adolescence, the severity of mental health problems in late teens also increased.
"Whilst 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," Toseeb said in a university news release.
"We comprehensively investigated a whole range of mental health outcomes, which included measures of both positive [well-being and self-esteem] and negative [symptoms of psychological distress] mental health," he added.
Being a victim of sibling bullying, the perpetrator, or both had a long-term effect on both positive and negative late teenage mental health, the researchers found.
The study noted that adolescence is a particularly vulnerable period for the deterioration of mental health. Sibling relationships can contribute to developing those issues.
Researchers suggested that prevention strategies and clinical interventions that reduce sibling bullying in early adolescence might improve mental health outcomes in the later teen years.
The findings were published Sept. 29 in the Journal of Youth and Adolescence.
The University of Pennsylvania has more about teen mental health.
SOURCE: University of York, news release, Sept. 29, 2021