A study has found that women who are directly exposed to semen on a regular basis are less depressed.

New Scientist reports the researchers think this is because mood-altering hormones in semen are absorbed through the vagina.

They say they have ruled out other explanations.

But wait there's more. An abstract for the studyconducted at State University of New York says, for females who did not use condoms, depression scores went up as the amount of time since their last sexual encounter increased.

It says: "These data are consistent with the possibility that semen may antagonize depressive symptoms and evidence which shows that the vagina absorbs a number of components of semen that can be detected in the bloodstream within a few hours of administration."

But don't give up on safe sex. New Scientist quotes study leader Gordon Gallup as saying, 'I want to make it clear that we are not advocating that people abstain from using condoms'

'Clearly an unwanted pregnancy or a sexually transmitted disease would more than offset any advantageous psychological effects of semen.'