An internet forum is probably not a good place to seek medical advice, a CPN, GP or pharmacist would be a better place to ask about interactions.

That said, personally, I have continued to smoke whilst taking Seroxat and several other SSRI type antidepressants. I've never noticed any symptoms that could indicate the drugs were interacting poorly with cannabis and my doc's has always been aware of my weed intake when prescribing.

So I don't think there is a big risk of anything major. The doc is always pretty good at telling about the health consequences of my behaviour, but I have never been told to stop smoking because of an SSRI. I couldn't smoke regularly whilst on a tricyclic because together they cause weird heart beat irregularities.

Do talk to your doc about your 'other drug use' when you ask about an AD. It is important for your doc to have accurate info about your habits before they make decisions about what is safe to prescribe.