Researchers at the University of Warwick found children who suffered physical or emotional bullying were twice as likely to develop psychotic symptoms by early adolescence, compared to children who are not bullied. However, if they experienced sustained bullying over a number of years that risk increases up to four times.

The research team, led by Professor Dieter Wolke, Professor of Developmental Psychology, followed 6,437 children from birth to 13 years.

The children took part in annual face-to-face interviews, psychological and physical tests. Parents were also asked to complete questionnaires about their child’s development. When they reached 13 years of age they were interviewed about experiences of psychotic symptoms in the previous six months.

Psychotic symptoms include hallucinations, delusions such as being spied on or bizarre thoughts such as one’s thoughts are being broadcast.

Professor Wolke said: “Our research shows that being victimised can have serious effects on altering perception of the world, such as hallucinations, delusions or bizarre thoughts where the person’s insight into why this is happening is reduced.”

“This indicates that adverse social relationships with peers is a potent risk factor for developing psychotic symptoms in adolescence and may increase the risk of developing psychosis in adulthood.”

The researchers used data from the Avon Longtitudinal Study of Parents And Children (ALSPAC). Parents have completed regular postal questionnaires about all aspects of their child’s health and development since birth (Apr 1991- Dec 1992).

Since the children were 7 and a half they have attended annual assessment clinics where they took part in a range of face-to-face interviews, psychological and physical tests.

Chronic peer victimisation, where bullying had continued over a number of years, was found in 13.7% of children when interviewed at ages 8 and 10. Severe victimisation, where children are both physically and emotionally bullied, was reported by 5.2% of children at age 10.

Professor Wolke added: “All children have conflicts occasionally and teasing and play fighting occurs. Children learn from these conflicts of how to deal with this. When we talk about bullying victimisation it is repeated, systematic and an abuse of power with the intent to hurt. Children who become targets have less coping skills, show a clear reaction and have few friends who can help them.”

Note: If no author is given, the source is cited instead.

• Children's Health
• Infant's Health

• Child Psychology
• Child Development

• Public Health
• Educational Policy

• Dopamine hypothesis of schizophrenia
• Postpartum depression
• Erikson's stages of psychosocial development
• Cyber-bullying
• Psychosis
• Separation anxiety disorder