Haha, you're the 2nd person to ask me if I'm really 17; the last person accused me of being 40. Yes, I'm 17 and will be graduating high school in a few weeks. Not sure why nobody believes this, but whatever. I'll be 18 in September, and I think it's funny how that 1 year can make such a monumental difference in how people perceive what you say/write.
Anyway, I have smoked weed on almost all of my meds, and the only one I regret doing so on was Risperdal (antipsychotic). Marijuana will affect the way your med works, but who knows how. It is more likely to affect it during the beginning, so my advice to people who wanna take substances while on an rx'ed med is to wait until they are stable (6-8 weeks).
If you are mentally stable, or feel better, after 6-8 weeks then start off slow with a little puff here and there. See how you feel. It may interrupt the effects of your med, and on Effexor, you would definitely feel this. Everybody is different, but I have had no troubles smoking on Prozac, Lamictal, and Zoloft. I've never tried an SNRI, so I dunno if this might make a difference. Try it and see how you like it. Anything you do safely and in moderation will not be irreparable, so just try it and see how it works for you.
If you do decide to try it, let me know how it goes.