Empirical validation of a predicted emotional modulation dimension linking temporal variability and individual differences in PTSD
Year: 2026
Type: preprint
Abstract: Current dimensional approaches to psychiatric disorders have largely focused on explaining differences between individuals, whereas it remains unknown whether symptom dynamics within individuals are organized by the same underlying dimensions. In PTSD, temporal symptom variability may represent a clinically meaningful source of heterogeneity relevant to spontaneous recovery, chronicity, and treatment response. Our reciprocal inhibition model of PTSD proposed that both between-individual heterogeneity and within-individual dynamics may be organized along a dimension reflecting the relative balance between re-experiencing and avoidance symptoms (symptom imbalance), potentially corresponding to shifts between states of emotional under- and overmodulation. Here, using seven longitudinal and two cross-sectional PTSD cohorts spanning disorder development, chronicity, and recovery, we examined whether symptom heterogeneity between individuals and within individuals over time is organized along shared latent symptom dimensions. Principal component analysis (PCA) performed separately on between-individual variability (individual differences) and within-individual variation (temporal variability) consistently recovered the same two axes: the first indexing overall symptom severity and the second reflecting the proposed symptom imbalance. To enable direct comparison across cohorts and between-individual and temporal scales, we integrated cohort-specific covariance structures using hierarchical multi-group PCA yielding universal axes (uPC1/uPC2). Mapping treatment trajectories onto this shared symptom space revealed that two first-line psychotherapies: cognitive processing therapy (CPT) and eye movement desensitization and reprocessing (EMDR): produced comparable reductions in overall symptom severity (uPC1), but opposite shifts along symptom imbalance (uPC2). These findings suggest treatment-related symptom trajectories that are not captured by severity alone and provide a quantitative basis for treatment stratification grounded in symptom imbalance dynamics, motivating prospective tests of state-dependent intervention in PTSD and related psychiatric disorders.
Source: medRxiv
Authors: Toshinori Chiba, Masaya Ito, Masaya Ichii, Kentarou Ide, Misa Murakami, Takero Terayama, Takatomi Kubo, Keiichiro Nishida, Nao Kobayashi, Taku Saito, Yuriko Takagishi, Florentine H. S. van der Does, Hironori Kuga, Masaru Horikoshi, Miyako Shirakawa-Nishi, Taishiro Kishimoto, Hiroyuki Toda, Tetsufumi Kanazawa, Nic J.A. van der Wee, Noam Goldway, Aurelio Cortese, Erik J. Giltay, Masanori Nagamine, Petra Ritter, Eric Vermetten, Talma Hendler, Mitsuo Kawato
Institutions: Advanced Telecommunications Research Institute International, National Center of Neurology and Psychiatry, Osaka Medical and Pharmaceutical University, National Defense Medical College, Nara Institute of Science and Technology, KDDI Research (Japan), KDDI (Japan), Leiden University Medical Center, Musashino University, Keio University, King's College London, Sungkyunkwan University, Charité – Universitätsmedizin Berlin, Tel Aviv University
Language: English
Subfield: Clinical Psychology
Field: Psychology
Domain: Social Sciences
Open Access status: green
Funders: Japan Agency for Medical Research and Development, National Defense Medical College, Deutsche Forschungsgemeinschaft, Institute for Basic Science, Berlin Institute of Health, Berlin University Alliance, HORIZON EUROPE Framework Programme, Japan Society for the Promotion of Science, Digital Europe
OpenAlex ID: W7202079625