The research by a British law firm found that most of the respondents described their first year as a 'whirlwind of wedded bliss', while the third year of marriage was said to be the happiest of all as couples, News.com.au reported.
The study of 2000 married people found that couples reported the fifth year as the most difficult to get through, due to factors such as tiredness and exhaustion because of soaring workloads.
Respondents voted the seventh year to be "the wall" which, if scaled successfully can pave the way for a long, lasting and happy relationship.
It was found that one out of 10 admitted "they didn't realise how hard" marriage would be, while others confessed to suffering an emotional "comedown" after the high of their wedding day.
The study also suggested that 50 percent of those surveyed asserted that their wedding day was the happiest of their life, while a third admitted the love in their marriage has reduced since the big day.