Scratch the 7-year itch

It is the theory immortalised by Marilyn Monroe in one of her most memorable performances - that happiness begins to decline after seven years of marriage.

But instead of The Seven Year Itch referenced in Monroe's 1955 comedy, a US study in which more than 2 000 women over 35 were questioned found that, in most marriages, happiness and communication between partners declined from the start - and never got any better.

The study claims that it is after 10 years that marital problems are at their worst.

But if couples can see their troubles through for another five years, things get better.