Overall 34 percent of women and 15 percent of men said they lacked interest in sex. Picture: Pixabay

London — Forget the seven-year itch – researchers claim it takes just one year for women to lose their passion in a relationship.

Their interest in sex tends to die down after a year living with the same partner, according to the largest study of sexual habits in the UK.

After 12 months sexual apathy among women quadruples, researchers at Southampton University discovered.

The feeling, however, is one-sided. Men are interested in sex no matter how long they have been in a relationship.

The findings, published in the third National Survey of Sexual Attitudes and Lifestyles, offer stark evidence that men and women view sex in very different ways.

Researchers from Southampton, Glasgow and University College London interviewed 6 669 women and 4 839 men aged between 16 and 74 who reported having at least one sexual partner in the last year.

Overall 34 percent of women and 15 percent of men said they lacked interest in sex.

Half of these – 62 percent of women and 53 percent of men – said that they were distressed by their lack of interest in sex.

And while interest in sex among women declines significantly with age, male sex drive seemed to fall far more gradually, with men found to stay interested well into their 70s.

The researchers, whose work was published in the medical journal BMJ Open, found openly talking about sex could help. Those who always found it easy to talk about sex with their partner tended to have a better sex life. This was true for men as well as women. Lead researcher Professor Cynthia Graham, from the Centre for Sexual Health Research at the University of Southampton, said: "Our findings show us the importance of the relational context in understanding low sexual interest in both men and women.

"For women in particular, the quality and length of relationship and communication with their partners are important in their experience of sexual interest.

"It highlights the need to assess and, if necessary, treat sexual interest problems in a holistic and relationship, as well as gender-specific, way."

The researchers found interest in sex gradually declined with age among women, with 25 percent of 11 to 24-year-olds saying they were uninterested in sex, a rate that rose to 39 percent among 55 to 64-year-olds. Among men, however, interest barely changes with age, briefly dipping between the ages of 35 and 44 before rising again in middle age and retirement.

Only 11 percent of men aged 16 to 24 said they were disinterested in sex, compared to 17 percent among 25 to 34-year-olds.

Even among 65 to 74-year-olds, just 14 percent of men said they were uninterested in sex. Men and women reportedly broadly similar rates of not feeling emotionally close to their partners during sex.

The researchers also found a similar balance among those who experienced their partner having sexual difficulties.

Both men and women said they were put off sex by past experiences of violent sex, poor mental and physical health, and recent sexually transmitted infections. Women who reported having three or more partners in the last year were less likely to be interested in sex, and having children under five or not sharing a partner’s sexual preferences was also found to be important.

Co-author Dr Kirstin Mitchell, of the University of Glasgow, said: "The findings on the strong association between open sexual communication and a reduced likelihood of sexual interest problems emphasise the importance of providing a broad sexual and relationships education rather than limiting attention only to adverse consequences of sex and how to prevent them."