It's known that some SSRIs alter neurosteroid levels. Neurosteroids and progesterone (which is generally high in PSSD) are two ligands that binds to the sigma receptors.
Sigma-1 mainly does control IP3/intracellular calcium levels but according to what it writes above it also effects SERT and 5HT2C. It seems like these receptors are in the center of many different theories but somehow is rarely being mentioned on forums.
