I debated about writing because I'm not sure I have the answer you want to hear...
This is my second IVF cycle, but I had done many many IUI's, some with stims. My first IVF resulted in my DD & my DP & I are trying for a sibling. I have had major depressive episodes for years in years past, but finally got my life together, went to grad school, got a good job, etc & am currently also on Wellbutrin (eerily similar)...
I gotta say that the BCPs, the stims, & the HCG shot have really messed with my head...I have felt deeply depressed (liked I used to years ago before I was really stable), almost to the edge of being safe, but I am somehow able to pull through it knowing what the end result will be...I think it is a major possibility that your DP, with such a history, might have similar issues. I'm not suggesting that you don't go through with it, just that you think it through thoughtfully:
Possibly useful advice if you & your partner decide to go through w/it.:
-I found that constant visits w/ a psychiatrist & therapist helped me get through it
-there are BCP's that are less mood-altering than others...ask about this
-there may be other avenues to suppression that BCPs...
-sometimes it is helpful to do what is now referred to as "psychiatric advanced directives"...Having your DP plan out, in advance of taking any new meds, exactly what she wants to do if she does get depressed (what has helped before? At what point should she stop the process for her own good? At what point will you respect her decisions if she is in a really bad place? Whom can she call if she is in a bad place? )
-I also remembered that when I finally got pregnant, those hormones took over & I felt more wonderful than I had in years (OK, I know the pregnancy part is not relevant, but focusing on the fact that this is for a finite period in time helps)
-think about Donor egg as a possibility...
I wish you & your DP the best of luck. Feel free to PM me.