Posttraumatic stress disorder (PTSD) develops in only a minority of trauma-exposed individuals and follows markedly divergent post-trauma courses. Explaining this distribution requires a framework that integrates non-transition, transition, persistence, clinical expression, and recovery rather than treating any single mechanism or phenotype as sufficient.

To synthesize established and contemporary trauma literatures into a multilevel account that treats PTSD as a conditional transition outcome rather than as the product of a single mechanism, circuit, or biomarker.

This integrative theoretical review draws on trauma psychology, emotional-processing and cognitive models, fear-extinction research, resilience and trajectory studies, network approaches, stress physiology, and biological psychiatry. Findings are organized across three analytic levels — landscape (transition and non-transition), network (maintenance after entry), and constellation (phenotypic and measurement-level representations) — with a transverse biological substrate axis.

The synthesis positions non-transition as the explanatory baseline; treats transition as configurational rather than determined by exposure alone; describes maintenance as plural, supported by partially separable behavioral and neurobiological processes; and treats recovery and relapse as asymmetric rather than simple reversals of pathogenesis. Diagnostic systems, the PTSD–complex PTSD distinction, trajectory classes, subtype axes such as the dissociative subtype, and demographic patterns provide clinically meaningful phenotypic and measurement-level representations that the framework must accommodate, while their correspondence to specific causal processes requires independent evidence.

The framework separates the problems of transition, maintenance, clinical expression, and exit, and specifies how biological evidence can inform each without being reduced to a single biomarker or pathway. Its principal value is to define longitudinal and translational tests that could move PTSD theory from cataloguing heterogeneity toward explaining it, while individual-level prediction remains a separate validation task.