Phase-based versus non-phase-based psychological interventions for complex PTSD: a systematic review and...

Area of Science:

• Psychiatry and Clinical Psychology
• Trauma and Mental Health Research
• Evidence-Based Psychological Interventions

Background:

• Complex post-traumatic stress disorder (CPTSD) is increasingly recognized following its inclusion in the ICD-11, highlighting its significant impact on functioning.
• A key debate in CPTSD treatment is the necessity of a stabilization phase (Phase 1) before memory exposure (Phase 2).

Purpose of the Study:

• To evaluate the comparative effectiveness of phase-based versus non-phase-based psychological interventions for reducing CPTSD symptoms.
• To investigate whether structured, multi-phase approaches yield superior outcomes compared to single-phase or non-phase interventions.

Main Methods:

• A systematic review and meta-analysis of randomized controlled trials (RCTs) published up to June 17, 2025, across major international and South Korean databases.
• Inclusion criteria focused on individuals with clinically significant CPTSD or PTSD with disturbances in self-organization (DSO) symptom clusters.
• Effect sizes were pooled using Hedges' g, with subgroup analyses and risk of bias assessments conducted.

Main Results:

• No significant differences in effectiveness were found between phase-based and non-phase-based interventions for most outcomes.
• Multi-phase interventions demonstrated superior effects on overall PTSD symptom reduction.
• Phase-based, multi-phase, and exposure interventions showed greater improvements in DSO affect regulation compared to their counterparts.

Conclusions:

• Findings suggest that non-phase-based and non-exposure interventions can be as effective as structured approaches for CPTSD in many cases.
• Certain outcomes, particularly disturbances in self-organization and affect regulation, may benefit more from phase-, multi-modular-, or exposure-based designs.
• Limitations include a small number of trials, single time-point data, and outcome measure heterogeneity, impacting precision and subgroup analysis.