More than a decade after breast cancer patients practiced techniques to reduce their stress levels during treatment, a new study finds that rates of depression and poor mental health still remain low. This has implications not just for everyday well-being, but for future risks of disease.

After several years of steady increases in breast cancer mortality rates beginning in the mid-1970s, the disease finally became less deadly by the 90s as screening and treatment became more advanced. Today, survival rates are the highest they’ve ever been. But as more people beat the disease, a greater number is living with the stressful aftershocks of costly and invasive treatment. Researchers argue this creates a need for standardized care that has so far been unmet.

Formally, the techniques are called cognitive-behavioral stress management (CBSM). Generally, they’re short-term strategies for controlling certain emotions through thoughts. But they’ve also been used to promote lasting mental health, as the techniques help people clear away the irrational assumptions and beliefs they may hold and substitute them with a clear-headed picture of the world. They also have been shown to improve physical health, as stress weakens the immune system. For people whose immunity is already compromised from prior disease, such as breast cancer survivors, maintaining lasting mental health can have whole-body effects.

“Since depressive symptoms relate to greater signs of inflammation in breast cancer patients and because inflammation promotes cancer disease progression,“ said senior author Dr. Michael Antoni to Medical Daily in an email, “then managing depressive symptoms during and after active treatment for breast cancer could have effects on health outcomes via lower inflammation.”

For the advances in screening, breast cancer is still the most common cancer among American women, according to the American Cancer Society. Roughly one in every eight women will develop the disease at some point in their lives, and it still makes up the second-highest number of cancer deaths, behind only lung cancer, in the U.S. Efforts are still needed to help women battle the myriad unforeseen consequences of life with the disease.

In their study, Antoni and his colleagues tracked 240 female breast cancer patients since the year 2000 who practiced CBSM techniques, which Antoni developed. The women learned how to promote relaxation and improve their coping skills in a support group setting. This went on for 10 weeks. After the initial trial the techniques seemed to be paying off. Within one year, the women had lower levels of stress.

In the years that followed, the researchers conducted several follow-up assessments. In 2014, for example, they found lower rates of depressive symptoms in women who had practiced the techniques even after five years since their enrollment in the study. The latest findings, published early in the journal Cancer, reveal after 15 years similarly low rates of depressive symptoms.

Jamie Stagl, lead author and researcher at Massachusetts General Hospital, said the techniques can also help women cope with the fears that their cancer may come back or progress even further. CBSM can change their view of disease, for instance, from one of self-defeating isolation, which can release harmful hormones, to one of positivity. Because of this, Stagl added in a statement, “the present results indicate that these skills can be used to reduce distress and depressed mood and optimize quality of life across the survivorship period as women get on with their lives.”

Source: Stagl J, Bouchard L, Lechner S, et al. Long-term psychological benefits of cognitive-behavioral stress management for women with breast cancer: 11-year follow-up of a randomized controlled trial. Cancer. 2015.