Women taking hormonal therapies as part of their breast cancer treatment experienced twice as many side effects if they held negative expectations, compared to women who believed the side effects would not be as bad, according to a new study. Side effects from treatment can influence how well a person adheres to it, the study authors argue, and understanding how expectations can impact side effects could spur the development of interventions to improve women’s experience.

Published in the journal Annals of Oncology, the study surveyed 111 women with breast cancer who were taking hormonal therapies, like the drug Tamoxifen, at the start of their treatment and again two years later. They were asked what their expectations were about the treatment, including the severity of the side effects. By the end of the study, the women who had negative or highly negative views of what they were going to experience reported having double the side effects as other women.

The side effects reported included weight gain, joint pain and hot flashes. But the researchers also noted that women reported side effects like back pain and breathing issues that, according to the study authors, could not be directly due to the drugs. Based on this, the researchers say negative thoughts about treatment may play a prominent role in people’s experience.

The study size is small, and more research is needed to determine if these expectations really play a significant role. But the findings suggest that more can be done to find ways to help women manage their expectations and have better outcomes. Counseling designed to boost coping expectations and strategies to help patients reframe how they view their own side effects—getting them to see that discomfort can mean the therapy is working, for instance—are some potential tools that can help outcomes, the study authors say.

 

This article originally appeared on Time.com.