Bullied Kids More Likely to Become Psychotic Preteens

Janis Kelly

May 08, 2009

May 8, 2009 — Children who are bullied are more likely to develop psychotic symptoms in early adolescence — and there is a dose effect, with repeated bullying associated with greater risk.

In the first prospective study to examine the relationship between childhood bullying and psychotic symptoms in early adolescence, investigators at the University of Warwick, in Coventry, the United Kingdom, found the risk for psychotic symptoms nearly doubled among children who were victims of bullying at age 8 or 10 years, independent of other psychiatric illness, family adversity, or the child's IQ, and increased nearly 4-fold when victimization was chronic or severe.

Study coauthor Dieter Wolke, PhD, told Medscape Psychiatry the findings have clear clinical implications.

"If children present with physical or mental health problems, also explore their peer relationships. Being victimized, in particular chronically or severely, can make you ill," Dr. Wolke, told Medscape Psychiatry.

The study is published in the May issue of Archives of General Psychiatry.

Significant Dose Effect

The researchers studied 6437 individuals in early adolescence (average age, 12.9 years) who were part of the Avon Longitudinal Study of Parents and Children (ALSPAC). Parents had completed regular mailed questionnaires about their child's health and development since birth, and the children underwent yearly physical and psychological assessments from the age of 7 years.

At each visit, trained interviewers rated the children on whether they had experienced psychotic symptoms, including hallucinations, delusions, or thought disorders, during the previous 6 months.

Children, parents, and teachers also reported on whether the child had experienced peer victimization, defined as negative actions by 1 of more other students with the intention to hurt.

The researchers categorized 46.2% of participants as victims and 53.8% as not victimized at either age 8 or 10 years. Dr. Wolke pointed out that this includes being victimized at any time in childhood, not just during the year in question.

At age 12.9, 13.7% of subjects had broad psychosislike symptoms with 1 or more symptoms suspected or definitely present; 11.5% had intermediate symptoms with 1 or more symptoms suspected or present at times other than going to sleep, waking from sleep, fever, or after substance use; and 5.6% had 1 or more symptoms definitely present.

The odds ratio for psychotic symptoms was 1.94 among victims of bullying at ages 8 and/or 10 years and jumped to 4.60 for repeated or severe victimization.

Victims Often Less Socially Skilled

Dr. Wolke said it is doubtful that being a target of peer victimization was the result rather than the cause of an underlying predisposition to psychotic symptoms.

"This is the issue of reverse causality," Dr. Wolke said. "We are fairly certain that this is not the case, as victimization reported by mothers from 4 years onward also related to psychotic symptoms. Also, it is not possible to measure psychotic symptoms before 8 years — believing in Santa Claus or fairies is not a delusion but part of appropriate development until that age."

"However," Dr. Wolke added, "we know victims show a reaction to bullying more often — by crying for example — are less socially skilled, and have no or few friends who can protect them. Thus, while the children may not have had psychotic symptoms, they may be socially awkward and were more likely to become targets. However, monozygotic twin studies that are discordant for bullying show that the victimized twin is more likely to develop depression and behavioral symptoms."

The researchers suggest further research is needed to sort out whether repeated victimization experiences alter cognitive and affective processing or reprogram stress response or whether psychotic symptoms are more likely due to genetic predisposition.

"Social victimization by peers is a severe stress. It may lead to reprogramming of the hypothalamic pituitary adrenal axis or a different cognitive style, both found in those with psychosis. It may be more severe in those with genetic susceptibility. However, these are speculations that require more research,” Dr. Wolke said.

"A major implication is that chronic or severe peer victimization has nontrivial, adverse, long-term consequences. Reduction of peer victimization and of the resulting stress caused to victims could be a worthwhile target for prevention and early intervention efforts for common mental health problems and psychosis," the authors conclude.

Cause and Effect Not Demonstrated

David Fassler, MD, from the University of Vermont College of Medicine, in Burlington, told Medscape Psychiatry that bullying is a common experience for many young people. 

"Surveys indicate that over half of all children are bullied at some time during their school years, and at least 10% are bullied on a regular basis,” Dr. Fassler said.

According to Dr. Fassler, previous research suggests bullying may increase the risk of developing psychiatric disorders such as schizophrenia or depression later in life. In this regard, the results of the current study are consistent with previous reports and demonstrate that children who are bullied during childhood are more likely to show "psychoticlike" symptoms by early adolescence. 

"Due to the design of the study, the authors can't actually prove that these symptoms are a direct result of the bullying. However, they do demonstrate a significant association," said Dr. Fassler. He warned that the results of this study should be interpreted with caution due to a number of methodological issues. 

"For example, the authors experienced a significant dropout rate over the course of the study. They were ultimately able to follow less than half their original sample. In addition, they didn't have access to baseline data on 'psychoticlike' symptoms for the children. However, despite these limitations, the article represents a useful addition to the literature on bullying.

"Hopefully, subsequent studies will help us identify kids who are particularly vulnerable, so we can intervene as early as possible to minimize the risk of lasting emotional consequences," Dr. Fassler said.

The UK Medical Research Council, the Wellcome Trust, and the University of Bristol provide core support for ALSPAC. This study was funded by a grant from the Wellcome Trust. The authors report no conflicts of interest.

Arch Gen Psychiatry. 2009;66: 527-536. Abstract


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