It seems simple — the closer you feel to your partner, the better your relationship; but it's not completely true. When it comes to a stable, long-lasting relationship, it is not how close you feel to your partner that counts the most, it's whether you're as close as you want to be, even if that's pretty far away.

According to a study from Columbia University, closer isn't always better. Being the right degree of closeness — or distance — from your partner is the best predictor of your own mental health and the relationship's health. That's why they're called personal relationships.

It didn't matter how close a person felt, it was how far away they were from their ideal closeness that predicted discord and depression.

The study looked at 732 individuals from the U.S. and Canada who were in relationships. Each person completed three yearly surveys about their relationship with their partner. To understand how close this person wanted to be to his or her significant other, the researchers used the Inclusion of Other in the Self test, in which a person chooses among six sets of interlinked circles that vary in how much they overlap the one that best illustrates their view of the relationship. The surveys also asked about the subject's own mental health and well being.

It didn't matter how close a person felt, it was how far away they were from their ideal closeness that predicted discord and depression. While it was true that feeling too distant was a more common problem (57%) than feeling too close (5%), both were associated with poorer relationship quality and depression. And feeling too close was just as harmful as feeling too far away.

Over the two years of the study, many relationships changed. Some people became closer to their ideal distance from their partner, while some grew further away. Those who approached their ideal reported better relationship quality and mental health. The opposite was also true: people who felt increasingly too close or too distant as the study progressed were more likely to have their relationship deteriorate or even break up.

So what can you take from this study other than that people differ in the kind and amount of closeness they are comfortable with? Well for one thing, you probably shouldn't just assume that your partner shares your views about closeness; you should talk with them about it. And the study may certainly have implications for therapists, who may be making too many assumptions about what would make a client's relationship healthier.

This study only looked at feelings of one partner in a relationship. Ongoing studies are now examining how both partners' perceptions of closeness affect a relationship. It might seem that a relationship where one partner wants to be closer and the other more distant would be doomed, but maybe true love can find a way around even this obstacle. Stay tuned.

An article on the study was published online in the Personality and Social Psychology Bulletin and will also appear in the April issue of the journal.