Brain zaps after trauma may stop PTSD before it starts

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Men and women 18-65 years of age. (Assessed via self-reported and medical record-based Date of Birth) * Trauma-exposed within the last 2 weeks (Endorsement of having experienced an event that could have caused death, serious injury, or sexual violence) * High initial symptoms of PTSD related to the index trauma - PCL-5 \>30 AND at least 2 symptoms of hyperarousal. * Low symptoms of PTSD related to a previous lifetime trauma - PCL-5\<31AND does not meet for all four DSM-5 clusters. * Participants may be on psychotropic medication, including antidepressants, antipsychotics, benzodiazepines and anticonvulsants, but the dosage of the medication must be stable for at least 6 weeks and not change during the course of the study (Assessed via self-report during the screening phone call). * Capable and willing to provide informed consent. Exclusion Criteria: * Having active suicidal intent or plan, or in the clinician's opinion, is likely to attempt suicide within the next six months. (Assessed via the Patient Health Questionnaire-9 (PHQ-9) during the screening phone call) * Lifetime diagnosis of psychotic disorder or bipolar disorder per psychiatric screener. (Assessed via self-report during the screening phone call) * Diagnosed with the following conditions: a neurological disorder, including a history of seizures, cerebrovascular disease, primary or secondary tumors in the central nervous system (CNS), stroke, cerebral aneurysm or movement disorder or any lifetime history of loss of consciousness for more than 5 minutes due to head injury (Assessed via self-report during the screening phone call) * History of cranial surgery, metallic particles in the eye or head (exclusive of mouth), implanted cardiac pacemaker or any intracardiac lines, implanted neurostimulators, intracranial implants (e.g., aneurysm clips, shunts, stimulators, cochlear implants, or electrodes), or implanted medical pumps. (Assessed via self-report during the screening phone call) * For women, being pregnant. (Assessed via self-report during the screening phone call, the medical record, and cycling females will undergo a pregnancy test at TMS Day 1)