An individual patient data (IPD) meta-analysis on negative effects of Mindfulness-Based Cognitive Therapy (MBCT) and Cognitive Behavior Analysis of Psychotherapy (CBASP) for patients with chronic and treatment-resistant depression

Background

Chronic and treatment-resistant depression (DTD) is difficult to manage, and while Mindfulness-Based Cognitive Therapy (MBCT) and Cognitive Behavioral Analysis System of Psychotherapy (CBASP) are recommended treatments, their potential negative effects—including deterioration, suicidality, and adverse events—are not well understood.

Objectives

This protocol outlines an individual patient data (IPD) meta-analysis to assess and compare the incidence and correlates of negative effects of MBCT and CBASP in adults with DTD. Secondary aims include examining effects on depressive symptoms and identifying moderators of negative outcomes.

Methods

Randomized controlled trials (RCTs) of MBCT and CBASP for adults (18–65 years) with chronic or treatment-resistant depression will be identified through systematic searches of major databases. Eligible studies must compare MBCT or CBASP (alone or with treatment as usual) to each other or to control groups. The primary outcome is clinically significant deterioration, defined as a ≥6-point increase on the PHǪ-9 or equivalent. Secondary outcomes are suicidality, adverse events, and depressive symptom change. IPD will be requested from authors; aggregate data will be used if IPD is unavailable. One-stage random effects meta-analyses and moderator analyses will be conducted.

Discussion

This IPD meta-analysis will provide robust estimates of negative effects for MBCT and CBASP in DTD, informing clinical practice and guidelines on patient safety.

PROSPERO registration number

CRD42022332039

Strengths and limitations

• Leveraging an individual patient data (IPD) meta-analysis allows for more precise assessment of negative effects and enables detailed moderator analyses that are not possible with aggregate data approaches.

• Standardizing outcome measures across studies using a common metric enhances comparability but may result in some loss of information or sensitivity to subtle differences in negative outcomes.

• Differences in the availability and reporting of individual-level variables across studies may limit the ability to fully explore all potential moderators of negative effects, and reliance on data sharing from original authors could restrict the inclusion of eligible studies.