Clinical Research Directory

Inclusion Criteria: * English as primary language, and comprehension suitable to understand experimenter instructions. * Current and chronic syndromic PTSD, defined as being exposed to a DSM-5 Criterion A traumatic event, with the presence DSM-5 qualifying PTSD symptoms for at least 3 months, as assessed by the Clinician-Administered PTSD Scale for DSM-5. * Able and willing to undergo functional magnetic resonance imaging (fMRI). * Willingness to participate in repeated assessments and as part of a delayed treatment group. Exclusion Criteria: * Evidence of current or prior history of psychosis or bipolar disorder as evidenced by self-report or clinical interview. * Active substance dependence within the past 6 months as evidenced by clinical interview. * Current regular psychiatric medication use (i.e. antidepressants), except for as-needed benzodiazepine or opiate medication no more than three times per week, on average, or for short-duration stimulant medication for attention deficit hyperactivity disorder that can be skipped within 24 hours of study visits. * A recent (\<6 months) suicide attempt or current active ideation with intent. * Unremovable ferrous metal in body. * History of neurological disorder, stroke, seizures/convulsions (except febrile seizures in childhood), epilepsy, brain surgery, electroconvulsive or radiation treatment, brain hemorrhage or tumor, or thyroid disorder. * Anyone who is pregnant or trying to become pregnant. * Current or past year (\> 3 sessions), psychotherapy with a prominent exposure or cognitive restructuring component. * Previous or current (es)ketamine treatment and/ or brain stimulation/neuromodulation treatment. * Other ongoing treatment that is likely to confound experimental effects. * Previous penetrating head injury/traumatic brain injury. Mild-to-moderate traumatic brain injury without penetrating injury is allowable.