PTSD Symptom Trajectories in the Wake of Traumatic Events: a Systematic Review and Meta-Analysis of 20 Years of Research

Posttraumatic Stress Disorder (PTSD) symptom trajectories considerably vary between individuals upon potentially traumatic events. In this systematic review, meta-analysis and meta-regression, we evaluated twenty years of literature on common variations in PTSD symptom trajectories. We specifically focused on longitudinal studies applying data-driven identification of latent trajectory subgroups based on symptom severity patterns over time Eligible studies applied statistical Growth Mixture Modeling to longitudinally assessed PTSD symptoms using validated continuous measures at minimally three time points across 12 weeks. Traditional systematic search methods, machine learning- and large language model–assisted approaches were combined to identify eligible articles published in any language until June 2025. To ensure coherence and consistency within subsequent data aggregation, we developed a standardized consensus-derived PTSD symptom trajectory classification framework. Pooled relative trajectory prevalence estimates were calculated using generalized linear mixed-effects models, and moderator analyses were conducted using meta-regression models. In total, we included 99 studies representing 113 independent samples and 215,136 participants from 21 countries. Five core PTSD symptom trajectories were identified. The pooled relative prevalences were 74.0% for the low symptoms trajectory, 31% for the moderate symptoms trajectory, 15.9% for the decreasing symptoms trajectory, 9.2% for the high symptoms trajectory, and 8.5% for the increasing symptoms trajectory. Several socio-demographic, trauma-related and methodological sample characteristics significantly moderated relative trajectory prevalences across samples. Our findings provide empirical support for and further refinements of leading theoretical conceptualizations of PTSD. Furthermore, the obtained relative prevalence estimates and their identified moderators may guide population-tailored mental health care following trauma exposure.