The risk of nonclinical psychotic symptoms doubles among 12-year-olds who
were bullied by other children when they were younger.
A study of more than 6,000 children in southwest Britain demonstrates a
significant association between peer victimization and psychosis, although not
causation. Nevertheless, it adds more evidence of environmental influences on
the origins of psychosis.
The prospective cohort study is the latest in a line of research suggesting
that childhood trauma may play some role in psychosis.
"Bullying is a common experience for many young people," said
child psychiatrist David Fassler, M.D., a clinical professor of psychiatry at
the University of Vermont College of Medicine in Burlington, in an interview."
Surveys indicate that over half of all children are bullied at some
time during their school years, and at least 10 percent are bullied on a
regular basis. It's well recognized that the experience of being bullied can
have a significant and lasting impact on a child."
The Avon Longitudinal Study of Parents and Children has followed children
born in the region between April 1991 and December 1992 with a series of
questionnaires, face-to-face interviews, psychological tests, and physical
examinations. The 6,437 children were asked at ages 8 and 10 if they had been
bullied by others and were asked about hallucinations and delusions at 12.9
years using the Psychosis-Like Symptoms Interview (PLIKSi). Overt bullying was
defined as being threatened, tricked, hit, or beaten up; called nasty names;
or having property taken. Children were also asked about "relational
victimization"—for example, whether others had excluded them from
play or told lies about them. Information was also gathered from parents and
The odds ratio for psychotic symptoms was 1.94 among children bullied at
ages 8 and/or 10, wrote Andrea Schreier, Ph.D., of the Health Sciences
Research Institute of the Warwick Medical School at the University of Warwick
in Coventry, England, and colleagues, in the May Archives of General
"It is not the actual type of victimization (overt or relational) but
the severity and chronicity of victimization that are most strongly related to
the likelihood of psychotic symptoms identified with the PLIKSi, indicating a
dose-response relationship," they wrote.
Findings were similar no matter which group of informants provided the
observations. Adjusting for family adversity, prior psychopathology, and IQ
altered the results very little, they said. That would lend weight to a
possible causal relationship between victimization and psychotic symptoms.
"The results of the current study are consistent with previous
reports suggesting that bullying may increase the risk of developing
psychiatric disorders such as schizophrenia or depression later in
life," said Fassler.
The researchers noted that victims differed from children who were not
bullied, according to existing research.
"As compared with those not victimized, victims of bullying are often
more withdrawn, unassertive, physically weaker, or easily emotionally upset;
have poor social understanding; have no or fewer friends; and are more often
bullied by their siblings," said the authors. "[V]ictimization may
be a marker of a developmental risk factor model of psychosis rather than a
However interesting, the study's results should be interpreted with caution
due to some methodological issues.
"The authors experienced a significant dropout rate over the course
of the study," said Fassler. "They were ultimately able to follow
less than half [46 percent] of their original sample. In addition, they didn't
have access to baseline data on 'psychotic-like' symptoms for the children.
However, despite these limitations, the article represents a useful addition
to the literature on bullying."
The relationship between genetic predisposition for psychosis and
victimization experiences must be addressed in future research, according to
the authors. Meanwhile, clinicians should be aware of this relationship and
ask about the bullying events when evaluating patients.
An abstract of "Prospective Study of Peer Victimization in
Childhood and Psychotic Symptoms in a Nonclinical Population at Age 12
Years" is posted at<http://archpsyc.ama-assn.org/cgi/content/short/66/5/527>.▪