The twenty-first century has seen a renewal of expectations in the domain of energetic metaphors to elucidate complex phenomena that range from the constraint mechanisms that guarantee the maintenance of living systems to hierarchical neural activity. The recent mathematization of the laws of conservation of energy that underlie the agenda of Helmholtz's perceptual theory and statistical physics has allowed isolated functions such as memory, attention and salience, but also entire psychopathological disorders, to fall under the umbrella of the same theoretical formulation: the free energy principle (FEP) developed in particular by Karl Friston. Based on the epistemic convergence that connects the FEP models and the Freudian psychic apparatus, this article proposes a metapsychological approach to the symptoms of post-traumatic stress disorder (PTSD). It pursues the recent effort to offer complementary interpretations to the overexpression of the fear response in the brain, the disruption of memory formation systems, or other models that have sought to explain the etiology of trauma and its symptomatology.