Genetic Variation Linked to Antisocial Behavior in Kids with ADHD
> 2/5/2008 1:19:51 PM

Behavioral problems are present in about half of ADHD cases, and children who struggle with antisocial behavior in addition to the primary symptoms of ADHD, which most often include hyperactivity, impulsiveness, or inattention, are at risk for many detrimental actions. They may grapple with substance abuse, academic failure, or criminal behavior, and these experiences can have lifelong consequences. In a new study, which was published in this month's Archives of General Psychiatry, researchers examined a common genetic variation thought to contribute to antisocial behavior in children with ADHD. Their findings demonstrate that children with a variation of the catechol O-methyltransferase gene (COMT) are more likely to engage in violent or aggressive acts and are at risk for committing crimes.

The researchers analyzed data from three separate studies: the Cardiff ADHD Genetic Study, which involved 376 Welsh and English children with ADHD, the Environmental Risk Study, a cohort study involving over 2,000 British twins born between 1994 and 1995 (with an ADHD prevalence of 8%), and the Dunedin Longitudinal Study, another cohort study that involved over 1,000 New Zealander children born between 1972 and 1973 (with an ADHD prevalence of 6%). The researchers assessed the subjects of the Cardiff ADHD Genetic Study for symptoms of conduct disorder, which include fighting, setting fires, and stealing. They assessed the subjects of the Environmental Risk Study and the Dunedin Longitudinal Study for aggressive and violent behaviors similar to the symptoms of conduct disorder.

Using DNA samples, the researchers divided the subjects into groups based on variations in the COMT gene. They identified those with two alleles of the amino acid methionine (Met/Met), those with two alleles of the amino acid valine (Val/Val), and those with one allele of each (Val/Met). Among subjects from the Cardiff ADHD Genetic Study, those with two copies of the Val allele were most likely to display antisocial symptoms. This susceptibility to aggression and violence was also observed among subjects of the two cohort studies. Again, those who had been diagnosed with ADHD and also possessed two copies of the Val allele were most at risk for these behaviors. Using these two studies, the researchers found no association between this genetic variation and antisocial behavior among those not diagnosed with ADHD. These associations remained significant after the researchers controlled for the severity of ADHD symptoms and IQ score.

With data from the Dunedin Longitudinal Study, the researchers also compared the criminal behavior of those with ADHD to that of those without the condition. Overall, 20% of these subjects had been convicted of a crime. Those with ADHD who also had two copies of the Val allele were more than twice as likely to have been convicted of a crime. Again, the researchers found no association between the Val allele and criminal behavior among subjects who had not been diagnosed with ADHD, an indication that this variation in COMT does not correlate to antisocial behavior in the general population. Rather, the genetic variation may interact with other genetic factors underlying ADHD.

The interaction of genetics and environmental factors plays a large role in the development of ADHD, and there are likely many other influences involved in the antisocial behavior accompanying some cases of ADHD. The results of this study provide further evidence that identifying those at risk for aggressive or violent behavior could be possible, and in doing so we might be able to facilitate earlier treatment.

No comments yet.

Post Your Comments

Post a comment
Email Address:
Verification Code:
Input the 8 characters you see above:


Drug Abuse
Sexual Addiction
Eating Disorders
Alzheimer's Disease

About TOL | Contact Us | Defining Behavioral Fitness | For Healthcare Professionals | Links | Privacy Policy