Methodological considerations and empirical data to the onset of efficacy of antidepressants and to the prediction of therapy outcome

Abstract

Is the onset of efficacy of antidepressants always delayed and which early clinical signs predict final outcome of therapy ? Our analyses show that strict response criteria produce necessarily later onset estimations rather than less strict ones. In two large-scale clinical samples we compared different estimation methods of the day of onset. Patients' direct ratings produced the earliest onset estimations. Because of the strong dependency of onset estimations on measurement methods, we argue that it is still open to debate, in which degree drug response is delayed. Concerning early clinical signs of final outcome we compared early changes of the Hamilton Rating Scale for Depression (HAM-D) items with several measures of final outcome. From the data we analyzed, there are no sufficiently precise signs of final outcome within the first 2 weeks of therapy.