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

Abstract

BackgroundCognitive 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.MethodIn a multicenter randomized trial, two hundred depressed patients will be recruited from Dutch specialized mental healthcare centers and randomized into one of the following groups, all receiving a maximum of 20 sessions in different frequencies: a) twice-weekly sessions at the start of CBT, b) twice-weekly sessions at the start of IPT, c) once-weekly sessions at the start of CBT, d) once-weekly sessions at the start of IPT. Primary outcome measures are depression severity, cost-effectiveness and quality of life. Process measures include therapeutic alliance, recall, therapy-specific skills, motivation and compliance. Assessments will take place during baseline, monthly during treatment and follow-up at month 9, 12 and 24. In addition, at 12 and 24 months, the frequency of depressive episodes in the previous year will be assessed. Blood samples will be taken pre- and post-treatment. The study has been ethically approved and registered.DiscussionFinding that twice-weekly sessions are more effective or lead to more rapid recovery of depressive symptoms could lead to treatment adaptations that have the potential to reduce the personal and societal burden of depression. In addition, insight into the mechanisms of change and physiological processes in psychotherapy will enable us to optimize treatments and may help to understand human functioning beyond the context of treatment.Trial registrationThe study has been registered on October 21th, 2014 at the Netherlands Trial Register, part of the Dutch Cochrane Centre (NTR4856).

The effects of once- versus twice-weekly sessions on psychotherapy outcomes in depressed patients

“…For a detailed description of these instruments and their psychometric properties, we refer to our protocol paper. 9…”

“…Our hypothesis is that a higher session frequency leads to better recall of the content of the sessions, which will lead to a better development of therapy-specific skills and consequently better treatment outcomes. 9 An alternative hypothesis is that a higher session frequency leads to a better working alliance, which then leads to better patient adherence and motivation, and consequently better treatment outcomes. This is the first randomised trial to investigate the effects of once weekly versus twice weekly sessions of CBT and IPT for depression.…”

Dull to Social Acceptance Rather than Sensitivity to Social Ostracism in Interpersonal Interaction for Depression: Behavioral and Electrophysiological Evidence from Cyberball Tasks

“…These interpersonal problems that may be due to negative cognitive deviation, anhedonia, and emotional regulation deficits have important roles in the onset and maintenance of the depressive state. In addition, many effective short-term treatment strategies target the improvement of interpersonal problems, such as interpersonal psychotherapy (IPT) (Bruijniks et al, 2015 ). However, the neuropsychological mechanisms of this impaired interpersonal function in depression are poorly understood.…”

Cognitive Therapy or Behavioral Activation for Major Depressive Disorder in Dutch Mental Health Care: Pilot Effectiveness and Process Trial

“…The study reported herein is a pragmatic pilot trial that has been conducted as part of a series of Dutch trials in outpatient settings. Despite the original CT manual (Beck, Rush, Shaw, and Emery 1979) recommending two weekly sessions in the beginning of therapy, most therapists in Europe generally see their patients only once per week (Bruijniks et al 2015). Therefore, the first aim of this trial was to test the implementation of a regimen of two psychotherapy sessions per week.…”

“…Therefore, the first aim of this trial was to test the implementation of a regimen of two psychotherapy sessions per week. Secondly, we wanted to inform a large ongoing study described in Bruijniks et al (2015) on the effects of session frequency and other mechanism of change in psychotherapy for depression. Thirdly, we intended to provide a benchmark for the effectiveness and mechanism trial by Lemmens et al (2015), which compared one session per week of CT to interpersonal psychotherapy (IPT).…”