A marriage in which one partner endures constant pain and the other must become a caretaker can survive - even thrive - according to new research at Brigham Young University.

"Most of us would imagine that living with pain all the time or taking care of someone with chronic pain would create serious negative effects on a marriage," said BYU associate professor Leslie Feinauer.But her research tells a different story. "We studied 141 marriages affected by medically diagnosed cases of chronic pain syndrome, but neither the patients nor the spouses appeared to have highly distressed marriages because of the illness."

Chronic pain syndrome is a serious debilitating problem. Source of the pain varies but common ailments include non-stop headaches and backaches. Effects may include years of relentless physical pain, loss of physical activity, weakened defenses against other illnesses, job absenteeism, depression and anxiety. Some sufferers become dependent on drugs.

Despite the grimness of an illness Feinauer says is "very real and disturbing," the couples studied were generally happy with their marriages.

"They want to get rid of the pain, not the spouse," says Feinauer.

Why the encouraging marital news? Feinauer and her associate William Steele offer the following suggestions, based on research results that have been accepted for publication in the American Journal of Family Therapy:

- Some people find caring for others a gratifying experience - especially if they feel appreciated.

- How well marriage partners communicate may help them through the illness. Ninety percent of participants in the study said they confided in their partners about everything.

- Some couples deal with the problems of chronic pain by saying it is beyond their control. Thus, the cause of sexual problems, financial distress, depression and other anxieties can be assigned to an outside source.

- Time can be a factor. If the first pain-producing stressors occur during more flexible periods in the marriage, the couple may adjust more readily. Such flexible periods include early in marriage when a couple is setting up the relationship, or later, after a couple has become stable and less threatened by changes.

- If the chronic pain sufferer lives in a culture where family unity and extended family support are important values, the couple may accept the problem or even attribute positive meaning to the experience.

- If religion plays an important role in their lives - as it did with 79 percent of the respondents - the couple may place high value on maintaining the marital relationship.

Despite the chronic pain syndrome, the majority said they would marry the same person again.