Anxiety Linked To Gene It Can Enhance, Or Hurt, Confidence

Scientists for the first time have identified a personality gene that seems to influence whether a person will be a hand-wringing worrier or a self-assured warrior.

The gene can act like natural Prozac in the brain, enhancing self-confidence and contributing to a cheerful temperament, according to a report in today’s issue of the journal Science.

But the researchers found that most people inherit a different version of the gene that apparently has the opposite effect, predisposing them to mild but chronic anxiety.

If confirmed and extended in follow-up studies, the finding could shed light on the genetics of personality and facilitate development of better mood-altering medications.

The work is the latest in a string of recent efforts to find the genetic basis of complex behaviors - a new scientific specialty that has stirred controversy over its tentative findings of genes for homosexuality, alcoholism, manic-depression and “novelty-seeking.”

Virtually all those findings have crumbled upon further analysis. And experts cautioned that the new gene, which in its most common form is linked to what psychologists call “neuroticism,” could succumb to the same fate.

But several researchers said they were inclined to believe the new results, given that the gene in question is known to regulate serotonin - the same brain chemical targeted by the antidepressant Prozac.

Others said the report appeared appropriately modest in its conclusion that the gene accounts for only about 4 percent of the difference between chronically anxious people and those who stride through life with cheerful aplomb.

The rest of the difference, scientists believe, is due to a dozen or more still-unidentified genes and a host of environmental factors, including parenting practices, that are as important as all those genes combined.

“Studies of twins that measure the influence of genes and environment on personality show that each contributes about 50 percent,” said David Goldman at the National Institute of Alcohol Abuse and Alcoholism in Rockville, Md.

The new study, led by KlausPeter Lesch of the University of Wuerzburg in Germany, with scientists from the National Institutes of Health, focuses on a gene that regulates a kind of molecular pump that in turn affects brain levels of serotonin - a chemical messenger known to affect mood and personality.