Can effexor/wellbutrin cause an increase in addiction or addictive symptoms?

Not that I know of. Effexor (venlafaxine) if taken for a period of five or six weeks and stopped suddenly can have significant withdrawal. Wellbutrin is used to help people who are addicted to cigarettes stop smoking but doesn't block withdrawal symptoms. That's as close to" addiction or addiction symptoms" as i can get regarding those two medications.