women appear to suffer from depression twice as often as men, and their brains typically produce about half as much serotonin - a brains chemical linked to depression. Recently Anna found that there seem to be significant differences in how male and female brains process serotonin. There are no firm conclusions yet, but this is of special interest for two reasons. First, common antidepressants like Prozac work on serotonin. Second, there is evidence that women respond better to these common antidepressants than those that work on neurotransmitters other than serotonin.