Why Does Our Brain Turn Threats Into Physical Symptoms?

Recent research shows that how we perceive threats can shape the learning of placebo and nocebo effects, and even contribute to functional somatic disorders (FSD). The High‑Risk Model of Threat Perception (HRMTP) identifies ten psychosocial factors—such as childhood trauma or hypnotizability—that heighten threat sensitivity. When these factors lower heart‑rate variability (HRV), the autonomic nervous system becomes dysregulated, fostering physical symptoms without an organic cause. In a sample of nearly 7,000 FSD patients, HRV was reduced compared to the norm. Moreover, 50% of chronic‑pain sufferers displayed a paradoxical hand‑temperature rise during a threat test, linked to adverse childhood experiences (ACE). The model proposes that neutral cues, when paired with unconscious threats, can amplify nocebo effects and weaken placebo responses in doctor‑patient interactions. Identifying these risk factors enables diagnosing FSD by inclusion of psychosocial causes rather than by exclusion.

The HRMTP model builds on three innate mechanisms described by the Conditioned Response Model (CRM): (1) associative encoding, where a neutral stimulus (CS) becomes a predictor of a physiological response; (2) top‑down modulation, where cognitive expectations influence limbic activity; (3) synaptic plasticity, which consolidates long‑term associations. Hypnotizability, measured with scales such as the Harvard Group Scale, acts as a moderator: highly hypnotizable individuals exhibit larger CS‑evoked responses, both in cortical activation (EE{G}) and