Objective: The literature on the relationship of depressive symptoms and stress hormones after cancer diagnosis has been mixed, with some studies showing a relationship and other studies showing none. Time since diagnosis may explain these contradictory findings. This study examined the relationship of depressive symptoms to stress hormones in patients with breast cancer using 12-month longitudinal data.
Methods: Patients with Stage II or III breast cancer (n = 227) were assessed every 4 months from diagnosis/surgery to 12 months. They completed the Centers for Epidemiological Studies Depression Scale (CES-D) Iowa Short Form and the Perceived Stress Scale and blood samples were obtained to measure stress hormones (i.e., cortisol, adrenocorticotropin hormone, norepinephrine, and epinephrine).
Results: Depressive symptoms were negatively related to cortisol levels (β= −0.023, p = .002) but were positively related to rate of change in cortisol (β = 0.003, p = .003). Adrenocorticotropin hormone, epinephrine, and norepinephrine did not covary with depressive symptoms (all p values > .05). When the CES-D and Perceived Stress Scale were both used to predict cortisol, only the CES-D was significantly related (β = −0.025, p = .017).
Conclusions: Depressive symptoms were negatively related to cortisol, but this relationship changed from the time of diagnosis/surgery through 12 months. Cortisol may initially provide a buffering effect against depression during the stress of initial diagnosis and treatment, but this relationship seems to change over time.