Design of an RCT on cost-effectiveness of group schema therapy versus individual schema therapy for patients with Cluster-C personality disorder: the QUEST-CLC study protocol.

BACKGROUND: Given the high prevalence of Cluster-C Personality Disorders (PDs) in clinical populations, disease burden, high societal costs and poor prognosis of comorbid disorders, a major gain in health care can be achieved if Cluster-C PDs are adequately treated. The only controlled cost-effectiveness study published so far found Individual Schema Therapy (IST) to be superior to Treatment as Usual (TAU). Group ST (GST) might improve cost-effectiveness as larger numbers can be treated in (>50%) less time compared to IST. However, to date there is no RCT supporting its (cost-) effectiveness. The overall aim of this study is to assess the evidence for GST for Cluster-C PDs and to improve treatment allocation for individual patients. Three main questions are addressed: 1) Is GST for Cluster-C PDs (cost-)effective compared to TAU? 2) Is GST for Cluster-C PDs (cost-) effective compared to IST? 3) Which patient-characteristics predict better response to GST, IST, or TAU? METHODS: In a multicenter RCT, the treatment conditions GST, IST, and TAU are compared in 378 Cluster-C PD patients within 10 sites. GST and IST follow treatment protocols and are completed within 1 year. TAU is the optimal alternative treatment available at the site according to regular procedures. Severity of the Cluster-C PD is the primary outcome, assessed with clinical interviews by independent raters blind for treatment. Functioning and wellbeing are important secondary outcomes. Assessments take place at week 0 (baseline), 17 (mid-GST), 34 (post-GST), 51 (post-booster sessions of GST), and 2 years (FU). Patient characteristics predicting better response to a specific treatment are studied, e.g., childhood trauma, autistic features, and introversion. A tool supporting patients and clinicians in matching treatment to patient will be developed. An economic evaluation investigates the cost-effectiveness and cost-utility from a societal perspective. A process evaluation by qualitative methods explores experiences of participants, loved ones and therapists regarding recovery, quality of life, and improving treatment. DISCUSSION: This study will determine the (cost-)effectiveness of treatments for Cluster-C PDs regarding treatment type as well as optimal matching of patient to treatment and deliver insight into which aspects help Cluster-C-PD patients recover and create a fulfilling life. TRIAL REGISTRATION: Dutch Trial Register: NL9209 . Registered on 28-01-2021.

Added value of Mindfulness-Based Cognitive Therapy for Depression: A Tree-based Qualitative Interaction Analysis.

AIM: To identify moderators of treatment effect for Mindfulness-Based Cognitive Therapy (MBCT) versus Treatment As Usual (TAU) in depressed patients. METHODS: An individual patient data-analysis was performed on three randomized-controlled trials, investigating the effect of MBCT + TAU versus TAU alone (N = 292). Patients were either in (partial) remission, currently depressed or had chronic, treatment-resistant depression. Outcomes were depressive symptoms and quality of life. The QUalitative INteraction Trees (QUINT) method was used to identify subgroups that benefited more from either condition. RESULTS: MBCT + TAU outperformed TAU in reducing depressive symptoms. For both conditions, the effect of baseline depressive symptoms on post-treatment depressive symptoms was curvilinear. QUINT analyses revealed that MBCT + TAU was more beneficial than TAU for patients with an earlier onset and higher rumination levels in terms of depressive symptom reduction and for patients with a lower quality of life in terms of improving quality of life. CONCLUSIONS: The results suggest that MBCT might be more beneficial for those with earlier onset and higher levels of rumination and for patients with a lower quality of life. Sophisticated analytical techniques such as QUINT can be used in future research to improve personalized assignment of MBCT to patients. Long-term outcome could also be integrated in this.

LONG-TERM OUTCOME OF MINDFULNESS-BASED COGNITIVE THERAPY IN RECURRENTLY DEPRESSED PATIENTS WITH AND WITHOUT A DEPRESSIVE EPISODE AT BASELINE.

BACKGROUND: In a previous randomized controlled trial in patients with three or more previous depressive episodes, mindfulness-based cognitive therapy (MBCT) appeared to be equally effective in those who were depressed and those who were in remission at the start of the trial. AIM: The aim of this study is to compare the 1-year outcome of MBCT in 124 remitted and 58 depressed patients who participated in the original trial and who were all offered MBCT either immediately or after a waiting period of 3 months. METHODS: The course of depressive symptoms, rumination, mindfulness skills, and quality of life over the course of treatment and the 1-year follow-up period was analyzed. Linear mixed modeling was used to compare the outcome between remitted and depressed patients at baseline. RESULTS: In the whole sample, levels of depression and rumination decreased and mindfulness and quality of life increased over treatment. Levels of depressive symptoms, mindfulness, and quality of life remained stable over the 1-year follow-up period. Rumination further decreased. Remitted and depressed patients at the start of the trial did not differ in terms of outcome during or after treatment. CONCLUSIONS: Long-term outcome after MBCT in depressed patients was comparable to those who were in remission at the start of the trial. These findings lend further support to the notion that recurrent depressed patients meeting the criteria of a depressive episode do not need to be excluded from MBCT.