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 .
Efficacy of venlafaxine and predictors of response in a prospective open-label study of patients with treatment-resistant major depression.
The aim of this study was to replicate the findings of a 1994 study , in which a 30 % response rate to venlafaxine was found in patients with treatment-refractory depression , as well as to examine for any predictors of such an outcome . The study was an 8-week , open-label , prospect i ve investigation of venlafaxine in doses up to 300 mg in 312 patients fulfilling criteria for either " absolute " or " relative " treatment resistance . By week 8 , 52.6 % of the patients had responded , which was defined as a 50 % reduction in scores on the Montgomery-Asberg Depression Rating Scale ; 49 % of those defined with " absolute resistance " demonstrated such an outcome . Forty-five percent of the patients with absolute resistance who had failed to respond to at least one tricyclic antidepressant responded to venlafaxine .  Response rates were higher in those with an absence ( 57.5 % ) compared with the presence ( 31.0 % ) of any comorbid psychiatric disorder ( p < 0.001 ) , " marked " ( 60.3 % ) compared with " mild or moderate " ( 51.6 % ) or " severe " ( 43.4 % ) baseline ratings on the patient-rated Clinical Global Impressions Scale ( p < 0.05 ) , and " relative " ( 61 % ) compared with " absolute " resistance ( 49 % ) ( p = 0.06 ) . Furthermore , improvement in scores of 20 % or 30 % at weeks 1 or 2 was associated with higher rates of final response ( p < 0.0005 ) . After logistic regression , both comorbid psychiatric illness ( p < 0.001 ) and early improvement ( p < 0.0001 ) remained significant and independent predictors of final response
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 .