New research has suggested that young children can experience serious mental problems if they are being bullied.
The risk of psychotic symptoms in youngsters, up to the age of adolescence, was four times higher if they were being bullied, a study found.
Psychologists followed 6,437 children from birth to 13 years and discovered that hallucinations, paranoid delusions and irrational thoughts were all symptoms.
Children involved in the study had psychological and physical tests and took part in annual face-to-face interviews, while parents were also asked about their child's development.
The researchers found that bullied children were twice as likely to develop psychotic symptoms by adolescence as those that did not experience bullying. However, the risk rose to four times as much if bullying was sustained over a long period.
Regular postal questionnaires about a children's health and development were completed by parents, for the research, which used data from the Avon Longitudinal Study of Parents And Children.
Chronic peer victimisation - continued bullying for a number of years - was reported by 13.7% of children between the ages of eight and 10, while physical and emotional bullying was experienced by more than 5% of 10-year-olds.