“In sickness or in health. . .”

That noble sentiment of the traditional marriage vow says your spouse promises to stick with you if you get sick. What it doesn’t say, and what a study by Washington State University psychologist John Ruiz (photo) and researchers at the University of Pittsburgh and Carnegie Mellon University now shows, is that your spouse’s personality can help you heal–or speed your demise.

And, in the happiest of endings, being satisfied with your partner, no matter what his or her personality, is like an inoculation against all the bad things wrought by depression and anxiety.

Drawing on a subject group of 111 couples in which the husband had coronary artery bypass surgery, Ruiz and his colleagues assessed aspects of personality, symptoms of depression, and overall marital satisfaction for each patient and spouse prior to the surgery and again 18 months afterward.

They found that in general, the personality of the wife predicted the depression level of the patient during recovery. A patient married to a neurotic and anxious spouse was more likely to report symptoms of depression 18 months following the surgery. The study focused on anxiety as a general personality trait, not as a natural response to one’s spouse experiencing a health crisis.

“In other words, the spouse’s personality–quite independent of the patient’s own personality–exerted a major influence on how well the patient was feeling and progressing towards recovery,” says Ruiz.

The link between patient depression and health problems isn’t new; over the past several years, doctors have recognized that cardiac patients who are depressed run a significantly higher risk of heart attacks and death than those with an optimistic outlook. What’s new is the demonstration of how profoundly cardiac patients can be affected by the people closest to them.

“We’ve known for some time that a patient’s personality and mood before surgery influence their own mental and physical recovery following surgery,” says Ruiz. “We also know that a partner’s personality and mood can affect us in the short term. What we were hoping to answer was whether a partner’s personality traits are also determinants of our own long-term emotional and physical recovery from a major health challenge.”

Now, thanks to Ruiz, we know that the personality of the patient’s spouse might be a big factor in aiding his recovery–or pushing him into depression.

“Our study suggests that there’s a distinct possibility that a spouse’s personality can increase depression, which may then lead to these negative physical outcomes,” he says.

Ruiz found that the cheerfulness factor works for both partners. Caring for a spouse after surgery can be demanding and stressful, even when the recovering patient is upbeat, he says; in his study, the wives caring for neurotic, anxious partners were more likely to show signs of strain and depression a year and a half after the surgery.

He says he doesn’t know yet what it is that more neurotic spouses do that causes depression in their partners.

“Are they creating more stress, or being less helpful, or burdening a person who is already having a difficult time with their own needs?” he says.

A more optimistic result of the study showed that marital satisfaction trumped the other findings.

“Being married to a neurotic, anxious person was only harmful for those who were unhappy in their marriage,” he says. “Heart patients who were happy in their marriage were able to overlook their spouse’s [neurotic] characteristics.”

Ruiz plans to examine the issue further as he follows the couples from the study and embarks on new projects exploring how our personality traits affect our family and friends. In the meantime, he says, if you’re facing cardiac problems and you’re happy in your marriage, don’t worry. Love conquers all.