Filing a regular audit on the state of your relationship could be the key to a happy marriage, as couples who analysed their disputes from a neutral perspective are reported to be less distressed, psychologists have claimed.

While some couples keep their relationship fresh with candlelit dinners or by taking up new hobbies, filling out a "relationship appraisal" could achieve even more impressive results, the Telegraph reported.

The advice may sound more appropriate to divorce lawyers than lovers, but dredging up recent arguments and frustrations in forensic detail three times a year can help couples achieve true marital bliss, a study found.

Filling out an appraisal online only takes seven minutes and can offset the decline in marital satisfaction that affects the average couple as time goes by, researchers claimed.

Eli Finkel, professor of psychology at Northwestern University in the USA, said that one can get pretty impressive results with minimal intervention.

"Not only did this effect emerge for marital satisfaction, it also emerged for other relationship processes, like passion and sexual desire, that are especially vulnerable to the ravages of time," Finkel said.

Researchers issued 120 couples with questionnaires on their relationship satisfaction, love, intimacy, trust, passion and commitment every four months for a two-year period.

At the same time, each person was asked to write a personal account of the biggest argument they had experienced with their partner during the preceding four months.

But half of the couples also completed a "reappraisal" where they were asked to assess the same disagreement from the imagined perspective of a neutral observer who has both sides' best interests at heart.

Both groups saw their marital quality decline during the first year of the trial, but this was completely reversed during the second year among the group which completed the reappraisals.

Couples in the two groups experienced the same number of fights over equally serious issues, but the couples who analysed the disputes from a neutral perspective were less distressed as a result, and reported being happier in their marriage.

The effects were the same whether the couples were newly-weds or had been married for 50 years.