Impulse Control Area In Brain Affected In Teens With Genetic Vulnerability For A

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Impulse Control Area In Brain Affected In Teens With Genetic

Vulnerability For Alcoholism

http://medicalnewscenter.com/recent/science-daily-medical-news.shtml

A new study suggests that genetic factors influence size variations

in a certain region of the brain, which could in turn be partly

responsible for increased susceptibility to alcohol dependence.

It appears that the size of the right orbitofrontal cortex (OFC), an

area of the brain that is involved in regulating emotional processing

and impulsive behavior, is smaller in teenagers and young adults who

have several relatives that are alcohol dependent, according to a

study led by Dr. Shirley Hill, Ph.D., professor of psychiatry,

University of Pittsburgh School of Medicine.

In the research, which was published this week in the early online

version of Biological Psychiatry, Dr. Hill and her team imaged the

brains of 107 teens and young adults using magnetic resonance

imaging. They also examined variation in certain genes of the

participants and administered a well-validated questionnaire to

measure the youngsters' tendency to be impulsive.

The participants included 63 individuals who were selected for the

study because they had multiple alcohol-dependent family members,

suggesting a genetic predisposition, and 44 who had no close

relatives dependent on drugs or alcohol. Those with several alcohol-

dependent relatives were more likely to have reduced volume of the

OFC.

When the investigators looked at two genes, 5-HTT and BDNF, they

found certain variants that led to a reduction in white matter volume

in the OFC, and that in turn was associated with greater impulsivity.

" We are beginning to understand how genetic factors can lead to

structural brain changes that may make people more vulnerable to

alcoholism, " Dr. Hill said. " These results also support our earlier

findings of reduced volume of other brain regions in high-risk kids. "

These differences can be observed even before the high-risk offspring

start drinking excessively, she added, " leading us to conclude that

they are predisposing factors in the cause of this disease, rather

than a consequence of it. "

The study was supported by grants from the National Institute on

Alcohol Abuse and Alcoholism.