London: Those who are bullied by peers in childhood are around five times more likely to experience anxiety and are nearly twice as likely to report more depression and self-harm at the age of 18 than children who are maltreated by adults, the findings showed.
The researchers compared the effects of maltreatment (by adults) and peer bullying in childhood on mental health outcomes in young adulthood.
"Until now, governments have focused their efforts and resources on family maltreatment rather than bullying," said lead researcher Dieter Wolke from the University of Warwick in Britain.
"Since one in three children worldwide report being bullied, and it is clear that bullied children have similar or worse mental health problems later in life to those, who are maltreated, more needs to be done to address this imbalance," Wolke explained.
"Moreover, it is vital that schools, health services and other agencies work together to tackle bullying," Wolke noted.
The findings are based on "Avon Longitudinal Study of Parents and Children" (ALSPAC) in Britain and the "Great Smoky Mountain Studies" (GSMS) in the US.
The current study includes 4,026 children from ALSPAC whose parents provided information on maltreatment between the ages of eight weeks and 8.6 years, and their child's reports of bullying when they were aged eight, 10 and 13; and 1,420 children from GSMS who reported information on maltreatment and bullying between the ages of nine and 16.
The harmful effects of bullying remained even when other factors that are known to increase the risk of child abuse and bullying, including family hardship and the mental health of mothers, were taken into account.
The study appeared in the journal The Lancet Psychiatry.