HAVING sex without a condom is good for your mental health, according to controversial research conducted by a leading Scottish psychologist.
Professor Stuart Brody concludes that unprotected heterosexual sex can significantly boost men and women's mental wellbeing.
Conversely, Mr Brody claims that heterosexual sex with a condom is associated with poorer mental health, problems with dealing with stress and even conditions such as depression.
The claims were immediately criticised by sexual health campaigners, who warned that unsafe sex leads to unwanted pregnancies and diseases.
Mr Brody, of the West of Scotland University, Paisley, believes that mankind is biologically programmed to enjoy unprotected sex because it gives couples an evolutionary advantage and maximises the chances of reproducing.
His conclusions, which are to be published in the academic journal Archives of Sexual Behaviour, angered groups anxious to promote the safe sex message and the role played by condoms in preventing unwanted pregnancies and sexually transmitted diseases.
Mr Brody said: "Evolution is not politically correct, so of the very broad range of potential sexual behaviour, there is actually only one that is consistently associated with better physical and mental health and that is the one sexual behaviour that would be favoured by evolution. That is not accidental."
Mr Brody based his conclusions on a study of the sexual behaviour of 99 women and 111 men in Portugal. They filled in questionnaires about the pleasure they derived from their sex lives and contraception use.
Using a measure of psychological health developed in Canada, Mr Brody concluded that condom use was associated with members of the sample who exhibited problems dealing with stress.
Those that had unprotected sex appeared to be able to deal with stress in a more mature way by taking effective action. They also had better mental health.
"The more often people are using condoms independent of age, independent of the nature of their relationship, the greater use of immature defence mechanisms against stress.
"In contrast, the more often they have sex without condoms, the better their mental health and the more mature their mechanisms."
His conclusions were attacked by family planning organisations and those promoting the safe sex message.
Tony Kerridge of Marie Stopes International, the leading sexual health and reproductive health organisation, said: "I would have thought that the mental health of anyone would be tested if they found out they had a sexually transmitted disease or that there was an unwanted pregnancy.
"Particularly in the case of casual relationships where there is no desire to get pregnant, advice should always be that condoms should be used.
"It really is a no-brainer as far as we are concerned.
"We are seeing some of the most rapidly increasing rates of HIV among heterosexual couples in Europe."