An anti-depressant drug has been found to help some women who suffer from a condition which leaves them with a low sex drive.

Wellbutrin WR, manufactured by the company Glaxo Wellcome, boosted interest in sex and increased arousal and sexual fantasies for some women suffering from hypoactive sexual desire disorder (HSDD).

Professor Taylor Segraves, of Chase Western Reserve University in Cleveland, US, said: "By the end of the (eight-week) treatment phase nearly 40% (of the 51 women subjects remaining in the trial) reported being satisfied with their sexual desire, whereas 100% were dissatisfied before starting treatment."

HSDD is believed to be very widespread among women and has proved to be resistant to therapy or drugs.

Sufferers have few or no sexual fantasies or appetite for sexual activity.

The loss of sexual desire can include all sexual activities or can apply to just a particular partner or sexual activity.

The individual does not become frustrated when deprived of sex and does not search for sexual stimulation.

HSDD can be linked to stress, depression, pain or low self-esteem.

Brain chemicals

In the study, which was presented at the American Psychiatric Association's annual meeting in Chicago, the women were first given a placebo for four weeks, then treated for eight weeks with bopropion hydrochloride sustained-released tablets, which is sold as Wellbutrin SR.

The drug enhances the presence of the brain chemicals norepinephrine and dopamine.

Dopamine is thought to be closely linked to the sensation of pleasure.

The drug has also been shown to reverse or minimise the sexual dysfunction experienced by some users of the family of anti-depressants such as Prozac, Paxil and Zoloft that are designed to enhance the neurotransmitter serotonin.