Hello again racjen,
This study shows there's a physiological estradiol (E2) regimen that is ideal for antianxiety and antidepressive behaviour, lower or higher doses don't have the same effect. Besides, stress and corticosteroids also play a role. The study was performed in rats (poor animals).
https://www.nature.com/articles/1300708Edit: I know you're may not able to read it right now, so here are the important bits:
'Together, these data suggest that moderate E2 levels, like that produced by 5 or 10 μg E2 administration, may decrease anxiety and depressive behavior and corticosterone levels and that these effects may be modulated by the tone of the HPA.'
'However, some E2 regimen of lower or higher E2 dosages, or a longer duration of E2 exposure, produce no effect on anxiety behavior, decrease anxiety behavior, or may indeed increase anxiety behavior of female rodents in these tasks.'
'We found an effect of moderate dosages (5–10 μg), but not lower (0–2 μg) or higher (20–50 μg) dosages, of E2 to reduce basal corticosterone levels and levels following behavioral testing with or without prior restraint.'
Plus the 2 last paragraphs that are too long to copy/paste on here.
Conolly X