According to the Bureau of Labor Statistics, in 2009, around of married women in the United States had higher incomes than their husbands, compared with 23.7 percent in 1987.
Despite the significant rise in the number of women taking the title of primary breadwinner, the gender stereotype remains that men should be the main earners in a household, and, as a result, many men feel they are expected to earn more than their partners.
But according to the new research, this expectation is bad news for men's mental health.
The investigators reached their findings by analyzing the data of married couples aged 18-32 who were part of the 1997-2011 waves of the National Longitudinal Survey of Youth.
The team looked at the income of partners in each couple over time, as well as information on the mental and physical health of each partner - as determined by scores on health questionnaires.
Overall, the researchers identified a reduction in psychological health and well-being among husbands who increasingly adopted more financial responsibility than their wives.
Men's mental and physical health fared worst in the years they were the primary breadwinners of the household, the team found.