Estrogen as an antidepressant

"Estradiol appears to function as an antidepressant through mechanisms inherent in traditional psychotropics (Duman et al 1997; Manji et al 2001) in widespread regions of the cortex and limbic brain (Gundlah et al 2000). Estradiol promotes neurite outgrowth and neuronal survival in hypothalamus, amygdala, hippocampus, dopaminergic neurons, and prefrontal cortex (Lee and McEwen 2001). Pro-monoaminergic effects of estradiol include enhancement of norepinephrine, dopamine (McEwen and Alves 1999), cholinergic (Gibbs and Aggarwal 1998), and serotonin systems (Bethea et al 2000; Osterlund et al 2000; Pecins-Thompson and Bethea 1999). Estradiol also mitigates against oxidative stress, glutamateric excitotoxicity, and β-amyloid toxicity (Amantea et al 2005). A potential role for estradiol to modulate feedback regulation of the hypothalamic-pituitary-adrenal (HPA) axis (Cizza et al 1997) is yet another mechanism by which estradiol may act as a psychotropic." http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2782667/?report=reader