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 .
L-5HTP in depression resistant to re-uptake inhibitors. An open comparative study with tranylcypromine.
L-5HTP and tranylcypromine were compared in an open , but controlled and cross-over study , in patients suffering from major depression ; all were non-responders to several reuptake inhibitors , including oxaprotiline and fluvoxamine .  After four unsuccessful sleep-deprivations , L-5HTP or tranylcypromine were given during four weeks in a crossover design . Of 17 patients given L-5HTP during both treatment periods , none responded , whereas of 26 patients treated with  tranylcypromine  , 15 responded . Thus , L-5HTP is not a therapeutically effective alternative in depressed patients who have not responded to reuptake inhibitors
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 .