The findings show that individuals who are bullied 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 age 18 than children who are maltreated.

The study, led by Professor Dieter Wolke from the University of Warwick, is the first of its kind to directly compare the effects of maltreatment (by adults) and peer bullying in childhood on mental health outcomes (anxiety, depression, self-harm, suicidal tendencies) in young adulthood.

The findings come from the Avon Longitudinal Study of Parents and Children (ALSPAC) at the University of Bristol, popularly known as Children of the 90s, and the Great Smoky Mountain Study in the USA (GSMS). This study included 4,026 children from ALSPAC whose parents provided information on maltreatment between the ages of 8 weeks and 8.6 years, and their child’s reports of bullying when they were aged 8, 10, and 13; and 1,420 children from GSMS who reported information on maltreatment and bullying between the ages of 9 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.

According to Professor Wolke:

Until now, governments have focused their efforts and resources on family maltreatment rather than bullying. Since 1 in 4 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. Moreover, it is vital that schools, health services, and other agencies work together to tackle bullying.