- Patients being treated with SSRIs, MAO inhibitors or tricyclic, tetracyclic or atypical antidepressants for pain may participate in this study if they are washed off these medications before study entry. Patients currently receiving therapy with SSRIs or tricyclic, tetracyclic or atypical antidepressants for depression may be washed off these medications before study entry pending permission of the prescribing physician and if they have never received a diagnosis of major depressive disorder or had a history of suicidal ideation.