There are so many antidepressants out there being used. What makes the SNRI better than an SSRI. I realize there are different neurotransmitters involved here.. But what is it about a persons depression, what symptoms seem to prompt use of the SSRI over and SNRI or vice versa. I want to know because my friend is going to try making the change from Celexa to Prestiq or some other SNRI.