Failure of Tibolone to Potentiate the Pharmacological Effect of Fluoxetine in Postmenopausal Major Depression

BACKGROUND: Perimenopausal depression has been attributed to physiological progressive estrogen decline. Estrogen and derivatives have some mood-enhancing effects, although studies of using estrogen as an antidepressant have had mixed results. The gonadomimetic drug tibolone stimulates estrogen receptors in a tissue-selective fashion, increasing the gonadal activity without causing some of the usual side effects of other estrogen preparations. METHODS: A total of 31 postmenopausal outpatients with a major depressive disorder (MDD) participated in the study. Sixteen received the antidepressant fluoxetine (20 mg/day) plus tibolone (2.5 mg/day), and 15 received the same dose of fluoxetine plus placebo, assigned in a randomized fashion. RESULTS: After 8 weeks of treatment, the two groups had a similar level of improvement in their depressive symptoms. Both treatments were well tolerated, without significant side effects. Pretreatment and posttreatment serum hormonal levels did not predict the final response. CONCLUSIONS: Combining tibolone and fluoxetine did not represent a more robust antidepressant response than fluoxetine alone in postmenopausal women with MDD.