Sex differences in the brain's serotonin system

February 13, 2008

A new thesis from he Swedish medical university Karolinska Institutet shows that the brain’s serotonin system differs between men and women. The scientists who conducted the study think that they have found one of the reasons why depression and chronic anxiety are more common in women than in men.

Serotonin is a brain neurotransmitter that is critical to the development and treatment of depression and chronic anxiety, conditions that, for reasons still unknown, are much more common in women than in men. A research group at Karolinska Institutet has now shown using a PET scanner that women and men differ in terms of the number of binding sites for serotonin in certain parts of the brain.

Their results, which are to be presented in a doctoral thesis by Hristina Jovanovic at the end of February, show that women have a greater number of the most common serotonin receptors than men. They also show that women have lower levels of the protein that transports serotonin back into the nerve cells that secrete it. It is this protein that the most common antidepressants (SSRIs) block.

“We don’t know exactly what this means, but the results can help us understand why the occurrence of depression differs between the sexes and why men and women sometimes respond differently to treatment with antidepressant drugs,” says associate professor Anna-Lena Nordström, who led the study.

The group has also shown that the serotonin system in healthy women differs from that in women with serious premenstrual mental symptoms. These results suggest that the serotonin system in such women does not respond as flexibly to the hormone swings of the menstrual cycle as that in symptom-free women.

“These findings indicate that when developing antidepressants and anti-anxiety drugs, scientists should evaluate their effect on men and women separately, as well as their effects before and after menopause,” says Ms Nordström.

Source: Karolinska Institutet

Explore further: Common antidepressant drugs linked to lactation difficulties in moms

Related Stories

Gene variations contribute to aggression and anger in women

March 9, 2007

Ever wonder why some women seem to be more ill-tempered than others? University of Pittsburgh researchers have found that behaviors such as anger, hostility and aggression may be genetic, rooted in variations in a serotonin ...

Sex differences seen in response to common antidepressant

August 29, 2008

Women with depression may be much more likely than men to get relief from a commonly used, inexpensive antidepressant drug, a new national study finds. But many members of both sexes may find that it helps ease their depression ...

German firm shelves libido-boosting drug for women

October 9, 2010

German drug firm Boehringer Ingelheim has shelved development of a libido-booster for women after it was given the thumbs down by the US Food and Drug Administration (FDA), the company said.

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

( -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.