London: Have you ever felt that your long relationship has no spark left and happiness has nose-dived considerably in your love life? Blame it on the famous seven-year itch phenomenon.

According to researchers, the seven-year itch is a psychological term that suggests that happiness in a relationship declines after around seven years of marriage. In a study of women's sex lives over a period of seven years, those whose relationship lasted the duration experienced the greatest loss of sexual desire.

The study, published in the journal Psychological Medicine, found that women who were in the same relationship at the end of the time period as at the beginning were found to have a level of sexual desire that was 53 percent lower than it was when asked seven years previously.

"But those who were in a different relationship after seven years or were single had a higher libido," found the researchers who surveyed some women in 2006 and returned to the same sample in 2013.

The study, published in the journal Psychological Medicine, found that women who were in the same relationship at the end of the time period as at the beginning were found to have a level of sexual desire that was 53 percent lower than it was when asked seven years previously

"The most pronounced observation for sexual desire was that women who were in the same relationship throughout the observation period had the greatest decrease in sexual desire," lead author Annika Gunst from University of Turku in Finland was quoted as saying in a Daily Mail report.

Moreover, women who found a new partner reported "somewhat lower decreases" while women who were single at the end of the period reported "stable sexual desire".

"Women who had a different partner from when they were first asked had a 28 percent drop in desire, while women who were single had the same level of sexual desire as when first asked," the study found.

Sexual satisfaction fell by 42 percent for the women in the same relationship, rose for women in new relationships by 30 percent, but fell for single women by 30 percent, the findings showed.

IANS