Bullying adversely affects children in later life more than being maltreated, according to new research from the University of Warwick.

A new study published in The Lancet Psychiatry shows that children who have been bullied by peers suffer worse in the longer term than those who have been maltreated by adults.

The research is led by Professor Dieter Wolke from Warwick's Department of Psychology and Warwick Medical School. The study is due to be presented at the Pediatric Academic Societies (PAS) annual meeting in San Diego on Tuesday 28 April.

There is already an established link between maltreatment by adults and the mental health consequences for children. Professor Wolke and his team wanted to examine whether long-term mental health issues among victims of bullying were related to having been maltreated by adults as well.

They looked at data from 4,026 participants in the UK ALSPAC study (Avon Longitudinal Study of Parents and Children) and 1,273 participants from the US Great Smoky Mountain Study.

For ALSPAC they looked at reports of maltreatment between the ages of 8 weeks and 8.6 years; bullying at ages 8, 10 and 13; and mental health outcomes at age 18. Data from the Great Smoky Mountain Study had reports of maltreatment and bullying between the ages of 9 and 16, and mental health outcomes from 19-25 years old.

Professor Wolke said: "The mental health outcomes we were looking for included anxiety, depression or suicidal tendencies. Our results showed those who were bullied were more likely to suffer from mental health problems than those who were maltreated. Being both bullied and maltreated also increased the risk of overall mental health problems, anxiety and depression in both groups."

In the ALSPAC study 8.5% of children reported maltreatment only, 29.7% reported bullying only and 7% reported both maltreatment and bullying. In the Great Smoky Mountain Study, 15% reported maltreatment, 16.3% reported bullying and 9.8% reported maltreatment and bullying.

Professor Wolke added: "Being bullied is not a harmless rite of passage or an inevitable part of growing up; it has serious long-term consequences. It is important for schools, health services and other agencies to work together to reduce bullying and the adverse effects related to it."