People who were bullied by siblings during childhood are up to three times more likely to develop psychotic disorders such as schizophrenia in early adulthood, according to new research.
In “Sibling bullying in middle childhood and psychotic disorder at 18 years: A prospective cohort study”, Slava Dantchev, Stanley Zammit and Dieter Wolke explored – for the first time – whether sibling bullying victimization or perpetration in middle childhood was prospectively associated with psychotic disorder in early adulthood.
The researchers investigated 6,988 participants of the Avon Longitudinal Study of Parents and Children, a UK community-based birth cohort. Sibling bullying was reported at 12 years and psychotic disorder was assessed via a semi-structured interview at 18 years.
The researchers found that involvement in sibling bullying was associated with psychotic disorder in a dose-response fashion, even after controlling for a range of confounders. Those involved several times a week were two to three times more likely to meet criteria for a psychotic disorder.
“Categorical analysis indicated that particularly victims and bully-victims were at increased risk of psychotic disorder. Involvement in both sibling and peer bullying had a dose-effect relationship with a psychotic disorder, with those victimized in both contexts having more than four times the odds for a psychotic disorder,” the researchers stated.
While no similar study exists to look at sibling bullying in the Philippines, an earlier 68-page report by the Human Rights Watch (called ‘Just Let Us Be’: Discrimination Against LGBT Students in the Philippines) documented the range of abuses against LGBT students in secondary school in the country. It found “widespread bullying and harassment, discriminatory policies and practices, and an absence of supportive resources that undermine the right to education under international law and put LGBT youth at risk.”
Researchers Dantchev, Zammit and Wolke recommended for “parents and health professionals (to) be aware of the adverse long-term effects of sibling bullying.”