What number of weeks are your supposed to be off an ssri before going on an maoi?

2 weeks: "Particular care must be exercised in switching patients from an MAOI to other antidepressant classes. For the patient who has completed an MAOI trial without therapeutic response, TCAs, SSRIs, bupropion, nefazodone, and other MAOIs should not be started until 10 to 14 days after the original MAOI has been discontinued. Although not currently designated an antidepressant, the serotonin agonist anxiolytic buspirone should also be included on this list. If possible, a similar waiting period should follow the discontinuation of a TCA or bupropion when an MAOI is to be administered. However, as noted above, MAOIs may be safely begun, with the appropriate precautions, even while a patient remains on some TCAs (Kahn et al. 1989)."