TMS-fNIRS Personalized Dosing

Inclusion Criteria 1. Adults ages 18-70 years. 2. Eligible for consideration of treatment with TMS for PTSD. 3. Diagnosis of PTSD based on CAPS-5. 4. No changes in psychotropic medication (if taking psychotropic medication) and/or changes in supportive psychotherapy for 1 month prior to initial visit; and clinically appropriate to maintain stable treatment regimen for duration of study. 5. Clinically competent to give informed written consent and ability to understand study procedures and to comply with them for the entire length of the study Exclusion Criteria: 1. Medical contraindication for neuromodulation (e.g., ferrous metal in head, seizure disorder, brain tumor, stroke, aneurysm, multiple sclerosis, etc.). 2. Unable to have an MRI (e.g., due to ferrous metal or inability to tolerate). 3. Active substance use disorder in last 3 months or any current substance use that puts the participant at increased risk or significant impairment 4. Dementia or other cognitive disorder making unable to engage in study. 5. Any history or diagnosis of Schizophrenia, Schizoaffective Disorder, Delusional Disorder or other psychotic illness. 6. Suicidal risk that precludes safe participation defined as clinical impression that the participant is at significant risk for suicide. 7. OCD cannot be the primary disorder but can have OCD symptoms 8. Taking any medication that significantly lowers the seizure threshold (e.g., tricyclic antidepressants, clozapine, etc.) 9. Current, planned, or suspected pregnancy 10. Unstable medical conditions or any current medical condition that could preclude being able to safely participate in TMS treatment (e.g., unstable metabolic abnormality, unstable angina, etc.) 11. Severe Traumatic Brain Injury 12. Prior TMS treatment or already received TMS as part of a study. 13. Significant ongoing litigation or claims that impact research activities, as determined by the research study team. (Research may especially be impacted when mental health or pain is being evaluated for litigation or claims, such as civil and criminal cases, disability claims and worker's compensation). We will exclude non-English speakers because of the need for rapid communication during the testing.