It's generally accepted that people who are married (particularly men) are healthier and happier than singletons.
But a new 11-year study turns these assumptions on their head, suggesting that actually those of us who are married are more likely to be miserable.
Marital difficulties, nagging and low-level stress caused by marriage tension all appear to make it more difficult for married people to respond well to positive experiences, a behaviour linked to depression.
The researchers at the University of Wisconsin-Madison in the US said that often marriages were a cause of chronic stress, which has a big impact on how people react to other things in their lives.
The researchers assessed a group of married adults for signs of depression, then questioned them again nine years later. Two years on they were given 'emotional response testing' to look at their responses to positive and negative experiences.
It was found that those who admitted tension in their marriage were less likely to repond to positive images - a marker for depression.
And it's all the more worrying as a separate survey has found that one in five couples has stayed together simply because they felt they couldn't afford to break up.
According to DebtAdvisoryCentre.co.uk, almost 10 million people in the UK have at some time in their life, stayed with a partner for financial reasons.
People between the ages of 25 and 34 are most likely to stay with a partner because of issues around joint finances and people in London feel the most trapped.
Spokesman for Debt Advisory Centre Ian Williams commented: “It’s shocking to hear that so many people feel forced to stay in a relationship for longer than they want to because of their finances, but it’s perhaps not that surprising. It’s tough to end the bonds we create in a relationship, and financial ties can often be the hardest to break.
“Joint debts, mortgages or rent and childcare costs all play a part in people choosing to stay in a relationship when love breaks down, if they think they’d be unable to afford these costs alone."
He added that last year 12 per cent of those coming to the Centre for debt help did so as a result of a relationship breakdown.
“If finances start to spiral out of control when a relationship ends, the sooner people seek help with their debts, the sooner they can start to work towards getting back in control of their money.”