Couples affect each other’s health majorly, a new study by the University of British Columbia suggests. Especially for couples faced with the medial conditions of old age; one partner’s health can be a crucial factor in the other’s wellbeing.

The study surveyed 1,700 couples between the ages of 76 and 90, with researchers examining psychological and physical medical records of a 15 year period. They concluded that one spouse’s illness could trigger mental illness like depression in both partners.

"When people are depressed, they tend to want to stay at home — but that causes a spouse to stay home more, too", Lead Researcher Christiane Hoppmann said. "That’s a problem, because when older adults stop being active — going for walks, socializing, shopping — they risk losing that functional ability".

While one spouse’s depression can rub off on the other, the opposite is equally true. A positive partner can help a sick person cope with their disease better. “We don’t know if this is good news or bad”, Hoppmann admitted.

Generally, if one spouse falls severely sick in old age, it is putting a big strain on the other. Dr. Suzanne E. Salamon, of Beth Israel Deaconess Medical Center in Boston, said that the burden of caring for a chronically ill person was often underestimated. Therefore, doctors should apply their focus beyond the individual and pay attention to their patient’s marital situation.