Gene, birth weight linked to antisocial behavior

NEW YORK (Reuters Health) – The presence of a specific gene
mutation and low birth weight appear to increase the risk of
early-onset antisocial behavior in children with
attention-deficit/hyperactivity disorder, according to findings
published in the Archives of General Psychiatry.

Dr. Anita Thapar and colleagues from Cardiff University,
Wales, examined whether a variation in two amino acids
associated with the catechol O-methyltransferase (COMT) gene
predicts antisocial behavior in a high-risk group of children.
The researchers also assessed the influence of birth weight.

The researchers conducted a family-based genetic study from
1997 to 2003. Included were 240 children recruited from child
and adolescent psychiatric and child health clinics who were
diagnosed with attention-deficit/hyperactivity disorder or
hyperkinetic disorder.

The subjects underwent comprehensive standardized
assessments, which included measures of antisocial behavior and
IQ. They also underwent testing for variations in two animo
acids — methionine or valine — in the COMT gene.

The results of indicate that children who had a COMT gene
mutation or low birth weight were significantly more likely to
have antisocial behavior.

The average conduct disorder scores were higher in children
with the gene mutation and those with birthweights lower than
2500 g. The association was independent of the effects of age,
sex, verbal IQ, and performance IQ.

“The results of this study have potentially important
implications insofar as they suggest that among those with ADHD
who are at high risk of early-onset antisocial behavior,” the
presence of a specific COMT gene mutation not only predicts
antisocial behavior, but also makes these children more
susceptible to the adverse effects associated with low birth
weight, Thapar’s team concludes.

SOURCE: Archives of General Psychiatry, November 2005.