Changes in the cortisol awakening response (CAR) following participation in mindfulness-based stress reduction in women who completed treatment for breast cancer.

Background: Changes in the cortisol awakening response (CAR) were studied in women participating in a Mindfulness-Based Stress Reduction (MBSR) program after completion of their medical treatment for breast cancer.

Method: Thirty-three women completed questionnaires pre- and post-MBSR pertaining to: stress, depressive symptomatology, and medical symptoms. The CAR was assessed on 3 days pre- and 3 days post-MBSR as a biological marker of stress.

Results: A significant effect on the CAR was found, with cortisol levels showing a prolonged increase after awakening at the post-MBSR assessment period. This was accompanied by significant improvements in self-reported stress levels, depressive symptomatology, and medical symptoms. Furthermore, the change in medical symptoms was negatively correlated with the area under the curve (AUC) at study onset (r = -.52, p < .002); i.e., the greater the AUC of the CAR before MBSR, the greater the reduction in medical symptoms after the program.

Conclusions: These results suggest the potential usefulness of employing the CAR as a biological marker in women with breast cancer participating in an MBSR program.