TY - JOUR AU - Bruijniks, Sanne J. E. AU - Bosmans, Judith AU - Peeters, Frenk P. M. L. AU - Hollon, Steven D. AU - van Oppen, Patricia AU - van den Boogaard, Michael AU - Dingemanse, Pieter AU - Cuijpers, Pim AU - Arntz, Arnoud AU - Franx, Gerdien AU - Huibers, Marcus J. H. PY - 2015 DA - 2015/06/30 TI - Frequency and change mechanisms of psychotherapy among depressed patients: study protocol for a multicenter randomized trial comparing twice-weekly versus once-weekly sessions of CBT and IPT JO - BMC Psychiatry SP - 137 VL - 15 IS - 1 AB - Cognitive behavioral therapy (CBT) and interpersonal therapy (IPT) are among the most well established therapies for the treatment of depression. However, some major questions remain unanswered. First, it is unknown what session frequency results in the most optimal (cost) effectiveness in psychotherapy. Second, the debate as to what mechanisms underlie the effect of psychotherapy has not yet been resolved. Enhancing knowledge about the optimal session frequency and mechanisms of change seems crucial in order to optimize the (cost) effectiveness of psychotherapy for depression. This study aims to compare treatment outcome of twice-weekly versus once-weekly sessions of CBT and IPT. We expect twice-weekly sessions to be more effective and lead to more rapid recovery of depressive symptoms in comparison to once-weekly sessions. Both therapy-specific and non-specific process measures will be included to unravel the mechanisms of change in psychotherapy for depression. Besides the use of self-reports and behavioral observations, this study will also examine underlying biological processes by collecting blood samples. SN - 1471-244X UR - https://doi.org/10.1186/s12888-015-0532-8 DO - 10.1186/s12888-015-0532-8 ID - Bruijniks2015 ER -