It may come as no surprise that happy people are healthy people (and vice versa). Researchers are finding that this may be especially important when it comes to cancer. Although treatments such as chemotherapy and radiation are typically essential for combating cancer, recent research shows that psychological health may be just as important to surviving—and perhaps even preventing—the disease. Eleven years ago, researchers at Ohio State University in Columbus began a clinical study called the Stress and Immunity Breast Cancer Project.

Women with breast cancer were divided into two groups: Some received counseling on topics such as learning how to reduce stress, improve quality of life, manage follow-up care, and communicate with doctors. They were also taught to recognize the stressors in their lives. The other group did not receive counseling. Recently, the researchers took a look at the long-term effects of the counseled versus un-counseled groups. The results, reported in the June issue of the journal Clinical Cancer Research indicate that the counseled women were less stressed, had healthier immune systems, and were less likely to experience cancer recurrence.

Of the women who were diagnosed with recurrent breast cancer, those who had undergone counseling as part of the project were more likely to survive. “Recurrence is devastating,” write the researchers, “but residual benefits from having earlier learned strategies for reducing stress and enhancing coping … [could improve] adaptation.” In other words, counseled women were better equipped to fight cancer.

Even if they were initially distressed by their diagnosis, they faired better than women who never received counseling. One aspect that influences stress, says the team at Ohio State, is an individual’s perception of support. A network of friends and family helps reduce disease-related stress and improves quality of life. In fact, women in healthy relationships may be at reduced risk of ever being diagnosed with breast cancer.

Last fall, researchers at the University of Chicago found that being alone may increase cancer risk. In a study of mice, the researchers demonstrated that certain tumor-related genes in mammary tissue became more active in the mice placed in isolation. Although further research is necessary to describe the relationships between stress and cancer, it appears that psychological and social health play important roles in fighting cancer.