The use of EMDR is determined by whether the complaint is purely organic or contributed to by experience. In those depressions that are fully organic antidepressants are clearly the treatment of choice. For those depressions that have an experiential contributor, for instance where the person "learned" that they were "worthless/powerless" and have earlier childhood experiences and/or present triggers that laid this groundwork than EMDR can be very effective. The client can have positive EMDR treatment effects if on antidepressants. The clinician should make the decision if stabilization on antidepressants is advisable during the EMDR treatment. The clinician than would decide when and if it is desirable to discontinue the medication. The only caveats offered are (1) remember that sometime the depression can be an interaction of both biochemistry and experiential contributors and (2) if the client is weaned off the medication, EMDR should be used to retarget the pivotal events and triggers to make sure that any state-dependent information is dealt with.
In general clinical practice, so far the only negative feedback we have received regarding medications is that in some instances the benzoes can inhibit treatment effects. However, this is not true for all clients.
If you have taken an EMDR Institute course, consider also joining the EMDR discussion list. Information is available at www.emdr.com.