some drugs, like anticonvulsants and antidepressants, describe the drug category and not the mechanism. the individual agents and drug classes in the anticonvulsant drug category act at many different receptors and it is not possible to generalize their potential for physical dependence or incidence or severity of rebound syndrome as a group so they must be looked at individually. anticonvulsants as a group however are known to cause tolerance to the anti-seizure effect. ssri drugs, which have an important use as antidepressants, engender a discontinuation syndrome that manifests with physical side effects; e.g., there have been case reports of a discontinuation syndrome with venlafaxine (effexor).