Women have sex on the brain

Sex really is all in the mind for women, scientists have confirmed.

After eight years of tests involving 3,000 women, the maker of Viagra has abandoned efforts to prove the anti-impotency drug can also work for females.

Pfizer has concluded the sexes have a fundamentally different relationship between arousal and desire.

Women's arousal is triggered by emotional, intellectual and relationshipbased factors rather than the simple physical response required by men, scientists discovered.

'The brain is the crucial sexual organ in a woman,' said Dr Mitra Boolel, the head of Pfizer's sex research team. While a man's arousal almost always led to a desire for sex, there was no obvious corresponding factor in females.

'With women, things depend on a myriad of factors,' he added.

However, Pfizer has not given up all hope of finding an alternative to Viagra for women.

Dr Boolel has told his team to concentrate on finding drugs that affect a woman's brain chemistry.

Pfizer, the world's largest private medical research and development organisation, spent hundreds of thousands of pounds on its research.

Early trials in the mid-1990s on women taking Viagra seemed to show it worked. But later studies found that, even though the drug increased pelvic blood flow, the women did not feel substantially aroused.