The number of previous treatments with antidepressants was negatively correlated with treatment outcome .
After a first SSRI , any switch within or between classes of antidepressants appears legitimate ( second SSRI , novel dual-acting antidepressants , selective norepinephrine or nor-adrenergic/dopaminergic agents , or tricyclic anti-depressant or mianserin ) .
No unequivocal evidence is available to prove an advantage of a between-class switch .
OBJECTIVE Selective serotonin reuptake inhibitors ( SSRIs ) are frequently used as a first antidepressant for major depressive disorder but have response rates of 50 % to 60 % in daily practice .
For patients with insufficient response to SSRIs , switching is often applied .
This article aims to systematic ally review the evidence for switching pharmacotherapy after a first SSRI .
A double-blind crossover trial of imipramine and phenelzine for outpatients with treatment-refractory depression.
OBJECTIVE Data from controlled studies concerning the response rates of patients to a second antidepressant medication after they have been unresponsive to a systematic trial of another antidepressant are extremely useful to clinicians for rational prescription of pharmacotherapy . Such information allows making an accurate prognosis , sustaining realistic hope in the patient , and achieving the best possible therapeutic outcome . This study was design ed to add to the scanty literature available on this subject . METHOD Eighty-nine mood-reactive , nonmelancholic , mainly chronically depressed out patients at a university research clinic who were unresponsive to vigorous double-blind trials of imipramine or phenelzine  were crossed over to treatment with the other drug under double-blind conditions . RESULTS Of 46 patients previously unresponsive to imipramine who completed phenelzine treatment , 31 ( 67 % ) responded to phenelzine . Of 22 patients previously unresponsive to phenelzine who completed imipramine treatment , nine ( 41 % ) responded to imipramine . The difference in response rates was statistically significant . Even after they had shown no response to 7 weeks of placebo and 6 weeks of imipramine treatment , 10 ( 83 % ) of 12 patients who then completed treatment with phenelzine responded . CONCLUSIONS These data suggest that among chronically ill , mood-reactive depressed patients with many symptoms of atypical depression , phenelzine is strikingly effective in those who have been nonresponders to imipramine and should be tried in such patients
The number of previous treatments with antidepressants was negatively correlated with treatment outcome .
After a first SSRI , any switch within or between classes of antidepressants appears legitimate ( second SSRI , novel dual-acting antidepressants , selective norepinephrine or nor-adrenergic/dopaminergic agents , or tricyclic anti-depressant or mianserin ) .
No unequivocal evidence is available to prove an advantage of a between-class switch .
OBJECTIVE Selective serotonin reuptake inhibitors ( SSRIs ) are frequently used as a first antidepressant for major depressive disorder but have response rates of 50 % to 60 % in daily practice .
For patients with insufficient response to SSRIs , switching is often applied .
This article aims to systematic ally review the evidence for switching pharmacotherapy after a first SSRI .