Individualized (fMRI-guided) TMS Intervention for PTSD

Brief Summary

The goal of this clinical trial is to learn how transcranial magnetic stimulation (TMS) affects brain circuits involving the amygdala in adults with posttraumatic stress disorder (PTSD). The main questions it aims to answer are: * Can MRI-guided TMS engage the amygdala by stimulating an individualized brain target connected to the amygdala? * Does stimulation of this individualized target engage the amygdala differently than stimulation of control sites? * Does a 6-week course of active TMS, compared with sham TMS, change amygdala responses and physiological responses to fear? Researchers will compare active TMS with sham TMS to evaluate changes in the targeted brain circuit and fear-related responses. Participants will: * Receive active or sham TMS every weekday for 6 weeks * Undergo MRI scans with TMS before and after the 6-week intervention to measure brain responses to stimulation * Participate in fear learning and memory tasks while physiological responses are measured * Undergo additional MRI scans, clinical assessments, questionnaires, and cognitive testing * Complete remote follow-up assessments at 1, 6, and 12 months after the intervention