Estrogen Receptor Beta and Mood

OBJECTIVE:

Depression risk increases during the perimenopause, and depression is cited as a primary reason for resuming menopausal hormone therapy (HT). Community-based epidemiologic studies document a 1.5-3 fold greater risk of first onset and recurrent depressions in women during the perimenopause compared with those who are premenopausal (or who are several years postmenopausal). Observational studies report the emergence of depressive symptoms after the discontinuation of HT in 5-10% of women. The role of estradiol (E2) - either declining or low levels - in the precipitation of perimenopausal depression (PMD) is unknown, largely due to the associational and indirect nature of the evidence linking ovarian function and depression. In study 03-M-0175, our results demonstrated that estradiol withdrawal was associated with a significant increase in depressive symptoms in those women with a past depression during the perimenopause. Of note, the effects of estradiol primarily occur through activation of two receptor subtypes, often with opposing outcomes: estrogen receptor (ER) alpha, and ER beta. Therefore, in this protocol, we examined the ability of a selective ER beta agonist (LY500307) to prevent estradiol withdrawal- induced mood symptoms in women with past perimenopausal depression. We focused on ER beta because the beta estrogen receptor is reported to mediate the effects of estradiol on the serotonergic system and mediate the antidepressant-like effects of estradiol in the forced-swim test. Moreover, selective agonists of estrogen receptor beta have been demonstrated to attenuate the behavioral and hypothalamic-pituitary-adrenal (HPA) axis response to stress.

Our objective is to examine the specific role of estrogen receptor beta in the effects of estrogen withdrawal in women with a past perimenopause-related depression. Results of this study will determine the role of ER beta in estradiol withdrawal-induced mood symptoms and can provide preliminary data to support the efficacy and safety of this compound as a treatment for depression during the perimenopausal transition.

STUDY POPULATION:

Healthy, non-depressed postmenopausal women, ages 45 to 65, with a well-documented past perimenopause-related depression (within 12 years) and whose mood systems got better with estradiol

DESIGN:

The medication phase of this study is a seven-week randomized, double blind, placebo controlled study and there is a four week follow-up evaluation phase to monitor all women for the emergence of adverse effects post-medication exposure. Participants will have weekly outpatient visits, weekly blood draws and will also complete daily symptom rating scales. The study involves a three week baseline phase in which all women receive open label (OL) estradiol therapy (ET) at a dose of 100 micrograms per day by transdermal skin patch, after which all women receive three weeks of double blind (DB) medication (i.e., LY500307 [at a daily dose of either 25 mg or 75 mg] or placebo). All participants will receive three capsules of LY500307 or placebo each morning consisting of the following formulations: 1) women randomized to 75 mg LY500307 will receive three capsules each containing 25 mg LY500307; 2) women randomized to 25 mg LY500307 will receive one capsule containing 25 mg LY500307 and two capsules of placebo; and 3) women randomized to placebo will receive three capsules each containing placebo. Then, in non-menstruating women (i.e., the absence of reported menstrual bleeding of greater than 1-2 days during the double blind phase of this study), the double blind phase will be followed by one week of Provera to precipitate a progestin-induced menses. The week of Provera is not a research-related intervention but is clinically-indicated to induce endometrial shedding that will eliminate potentially abnormal endometrial tissue consequent to the three weeks of unopposed estradiol exposure.

Inclusion criteria

• Women with a past perimenopause-related depression (within 12 years). The diagnosis of perimenopause-related depression will be based on a history of a past depressive episode (major or minor depression confirmed by Structured Clinical Interview for Diagnostic and Statistical Manual (DSM)-V (SCID)) at midlife in association with menstrual cycle irregularity (and possibly hot flushes and/or vaginal dryness) and in whom menopausal hormone therapy was reported to improve their depression at any time within the prior twelve years. All women participating in this protocol will be screened with psychiatric, medical, and reproductive evaluations to confirm they are in good medical health.
• Age 45 to 65
• Medication free (including no mood stabilizers, no sleep medication) except for the following: women on menopausal hormone therapy who will discontinue these medications at the start of this study and have their hormone therapy replaced with estradiol 100mcg per day (as described below), women who are on stable doses of thyroid replacement for at least six months prior to study enrollment, or women who occasionally take non-steroidal anti-inflammatory drugs [NSAIDs] or allergy medications (although we will ask women to minimize the use of these medications during the study).
• Subjects must have consent capacity

Exclusion criteria

The following conditions will constitute contraindications to participate in this protocol:

• Any current Axis 1 psychiatric illness or any clinically significant sleep disorder;
• Women with histories of hormone replacement therapy-induced dysphoria due to either the estrogen or the progesterone components of their hormone replacement;
• Past history of major depression with suicidal ideation;
• History of ischemic cardiac disease, pulmonary embolism, or thrombophlebitis;
• Renal disease; hepatic dysfunction; history of cholecystitis; hypertension;
• Women with a history of carcinoma of the breast or any undiagnosed breast nodule/mass;
• Women with a history of uterine cancer, ill-defined pelvic lesions, particularly undiagnosed ovarian enlargement, undiagnosed vaginal bleeding;
• Pregnant women; sexually active women will be required to employ barrier contraceptive methods;
• Cerebrovascular disease (stroke);
• Recurrent migraine headaches;
• Women who have had a hysterectomy before one year after their last menstrual period.

National Institute of Mental Health (NIMH) employees/staff and their immediate family members will be excluded from the study per NIMH policy.