Menopause is a normal part of the life cycle for women, usually occurring some time in mid to later life. Given the age demographics of breast cancer, a majority of women with the diagnosis are also postmenopausal (
+7). In addition, an estrogen deficiency or a premature menopause state can be induced among patients with breast cancer by antiestrogen treatments, which include tamoxifen, raloxifene, and letrozole. In the general population, increased depression associated with estrogen-reduced states, such as menopause, has been reported, and there have been clinical observations that depression can be an adverse side effect of tamoxifen treatment. Attention to this topic was ignited a few years ago by a small, uncontrolled study of 21 patients who were likely to become acutely estrogen deficient during treatment for breast cancer, some because of tamoxifen treatment (
+8). Thirty-eight percent of the women reportedly developed major depressive disorder. However, larger, controlled studies have not found an association between tamoxifen treatment and depression. For example, the National Surgical Adjuvant Breast and Bowel Project (NSABP) Breast Cancer Prevention Trial followed 11,064 women who were given tamoxifen or placebo for three years and found no significant differences in depression levels between the two groups (
+9).
Although women with breast cancer may be menopausal or taking tamoxifen, another issue to consider is whether or not they have physical side effects from being in an estrogen-deficient state. Symptoms of menopause, such as hot flashes, sweats, vaginal dryness, and dyspareunia, can have a direct impact on quality of life and psychological well-being (
+7). Menopausal symptoms have been shown to trigger or intensify depression among women with coexisting stressors, a previous history of depression, or a negative attitude toward menopause (
+7).
Consistent with these findings, depression in postmenopausal women with breast cancer has been shown in other studies to be closely associated with a high level of health complaints (
+10). Such complaints may be related to the illness burden of cancer or may result from cancer treatments. For example, breast irradiation can cause progressive fatigue, resulting in delayed return to usual activities, which may increase vulnerability to depression. Likewise, patients with breast cancer who receive high-dose chemotherapy may be at risk of severe fatigue, which has been associated with depression, pain, and sleep disturbances (
+11). The pain from chemotherapy-induced neuropathies also may worsen symptoms.