Efficacy of antidepressants: similar but different

Fountoulakis & Moller (2010) have re-analysed the Kirsch et al. (2008) meta-analysis of newer antidepressants and reached quite different conclusions to the original study. In particular they highlight that both venlafaxine and paroxetine exceed the NICE criteria for ‘clinical significance’ of 3 points on the Hamilton Rating Scale for Depression (HAMD) and that the Kirsch et al. analysis underestimates the effect size of newer antidepressants due to methodological reasons. They also go on to claim that placebo response in trials declines with increasing baseline severity while antidepressant response remains the same. They argue this means that while much of the placebo response is due to expectancy effect this is not true for antidepressants and that therefore the effects are not additive, undermining the validity of randomized controlled trials.We have also performed a re-analysis of the Kirsch et al. data (Horder et …