Reduced serotonin transmission affects men and women differently, a new study finds. Serotonin is a neurotransmitter in the brain, and low levels of serotonin have been associated with both anxiety and depression. When serotonin levels were manipulated in study participants, men became more impulsive but did not experience mood changes. Meanwhile, women reported worsening moods and also became more cautious.

The study's results may explain "why women show a higher prevalence of mood and anxiety disorders compared to men, while men show a higher prevalence of alcoholism, ADHD and impulse control disorders," said Dr. Espen Walderhaug, one of the study's authors in a press release. Theorizing why women and men react differently, Dr. Walderhaug said, "Although we have the same serotonergic system in the brain, it is possible that men and women utilize serotonin differently."

The study was published in the September 15, 2007 issue of Biological Psychiatry.

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