Intraindividual variability and emotional change as predictors of sudden gains in imagery rescripting and EMDR for PTSD in adult survivors of childhood abuse

Abstract

Sudden gains, defined as large and stable improvements in symptom severity during psychological treatment, have consistently been found to be associated with better outcomes across treatments and diagnoses. Yet, insights on coherent predictors of sudden gains and on emotional changes around sudden gains in post‐traumatic stress disorder (PTSD) are lacking. We aimed at replicating a measure of intraindividual variability as a predictor for sudden gains and testing its independence from change during treatment. Furthermore, we expected changes in emotions of guilt, shame and disgust prior to sudden gains to predict sudden gains. Data from a pre‐registered randomized controlled trial (RCT) of eye‐movement desensitization and reprocessing (emdr) and Imagery Rescripting (ImRs) for PTSD in 155 adult survivors of childhood abuse were used. Intraindividual variability of PTSD symptoms in both treatments did not predict sudden gains status and was not independent of change during treatment. In the EMDR condition, levels of shame during treatment predicted sudden gains and shame decreased shortly before a sudden gain in both treatments. Reductions in all emotions during sudden gains were significantly higher for participants with sudden gains than for comparable intervals in non‐sudden gainers. Our findings do not support the predictive validity of intraindividual variability for sudden gains. The decrease of guilt, shame and disgust during sudden gains warrants further research on their role as a mechanism of treatment change for PTSD.

Sudden gains in routine clinical care: application of a permutation test for trauma-focused cognitive behavioural therapy

“…The majority of SGs occurred during the phase of active trauma processing. Together with other evidence on the timing of SGs in relation to treatment manuals (Kuck et al, 2023 ), this suggests that SGs are connected to specific treatment mechanisms. In addition, no predictors of SGs or sudden losses were identified.…”

“…This result has to be integrated with the finding of an increased incidence of SGs during the trauma-focused treatment phase (vs. in the phases of preparation and reclaiming-your-life assignments) and findings from other studies (e.g. Kuck et al, 2023 ; Wiedemann et al, 2020 ), which connect SGs to specific behaviour change processes. We posit that during behaviour change processes, a certain amount of symptom reduction is categorized as SGs, with a portion of these categorizations occurring randomly.…”

“…The authors defined IV as the variability of a subject’s weekly symptom score, computed an index of this fluctuation and found it to correlate with the occurrence of SGs, independently of the change during treatment. However, this finding has not been replicated in another study and the described findings on intra-individual variability do not appear to generalize easily across treatments and disorders (Kuck et al, 2023 ). Explanations may be that more chronic psychopathology (as found in the study by Kuck et al, 2023 ) leads to less spontaneous variability or that there are other moderators to consider that exert an influence on variability.…”

“…However, this finding has not been replicated in another study and the described findings on intra-individual variability do not appear to generalize easily across treatments and disorders (Kuck et al, 2023 ). Explanations may be that more chronic psychopathology (as found in the study by Kuck et al, 2023 ) leads to less spontaneous variability or that there are other moderators to consider that exert an influence on variability.…”

“…Furthermore, SGs appear to have significant effects on other relevant factors including increases in therapeutic alliance (Lutz et al, 2013 ; Wucherpfennig et al, 2017 ), changes in coping skills (e.g. patients’ experiences of clarification of meaning and problem solving; Wucherpfennig et al, 2017 ), as well as changes in negative emotional states associated with PTSD (Kuck et al, 2023 ).…”