Objective: The first aim of this study was to test the potential predictive value of variables commonly associated with PTSD resulting from a history of repeated childhood abuse, in relation to treatment outcomes. The second aim was to examine if complex PTSD symptoms act as potential moderators between treatment conditions and outcomes.

Method: Data were obtained from a randomized controlled trial comparing a phase-based treatment (Skills Training in Affect and Interpersonal Regulation [STAIR] followed by Eye Movement Desensitization and Reprocessing [EMDR] therapy; n = 57) with a direct trauma-focused treatment (EMDR therapy only; n = 64) in people with PTSD due to childhood abuse. The possible predictive effects of the presence of borderline personality disorder, dissociative symptoms, and suicidal and self-injurious behaviours were examined. In addition, it was determined whether symptoms of emotion regulation difficulties, self-esteem, and interpersonal problems moderated the relation between the treatment condition and PTSD post-treatment, corrected for pre-treatment PTSD severity.

Results: Pre-treatment PTSD severity proved to be a significant predictor of less profitable PTSD treatment outcomes. The same was true for the severity of dissociative symptoms, but only post-treatment, and not when corrected for false positives. Complex PTSD symptoms did not moderate the relationship between the treatment conditions and PTSD treatment outcomes.

Conclusions: The current findings suggest that regardless of the common comorbid symptoms studied, immediate trauma-focused treatment is a safe and effective option for individuals with childhood-related PTSD. However, individuals experiencing severe symptoms of PTSD may benefit from additional treatment sessions or the addition of other evidence-based PTSD treatment approaches. The predictive influence of dissociative sequelae needs further research.

The study design was registered in The Dutch trial register (https://www.trialregister.nl/trialreg/admin/rctview.asp?TC = 5991) NTR5991 and was approved by the medical ethics committee of Twente NL 56641.044.16 CCMO.

Highlights:

• One of first studies that aimed to identify multiple potential predictors and moderators in patients with PTSD related to childhood abuse.
• Only severe PTSD predicted worse treatment outcomes.
• The predictive influence of dissociative sequelae needs further research.”