Inclusion Criteria:
1. Male or female veteran, 18 to 70 years of age, inclusive, at screen.
2. Able to read, understand, and provide written, dated informed consent prior to screening. Participants will be deemed likely to comply with the study protocol and communicate with study personnel about adverse events and other clinically important information.
3. Has a history of head trauma, combat or blast exposure.
4. Scheduled themselves for ibogaine-magnesium therapy at Nouvelle Vie in Mexico.
5. Participants must be willing and able to travel to Stanford University before and after ibogaine-magnesium therapy.
6. Capable of getting an MRI scan.
7. Willing to be video recorded during the consenting process. (to be stored on a secure server, no PHI associated with video recordings)
8. Body mass index between 17-35kg/m2.
9. If female, a status of non-childbearing potential or use of an acceptable form of birth control per the following specific criteria:
1. Non-childbearing potential (e.g., physiologically incapable of becoming pregnant, i.e., permanently sterilized (status post hysterectomy, bilateral tubal ligation), or is post-menopausal with her last menses at least one year prior to screening); or
2. Childbearing potential, and meets the following criteria:
i. Childbearing potential, including women using any form of hormonal birth control, on hormone replacement therapy started prior to 12 months of amenorrhea, using an intrauterine device (IUD), having a monogamous relationship with a partner who has had a vasectomy, or is sexually abstinent.
ii. Negative urinary pregnancy test at screening, confirmed by a negative urinary pregnancy test at randomization prior to receiving study treatment.
iii. Willing and able to continuously use one of the following methods of birth control during the course of the study, defined as those which result in a low failure rate (i.e., less than 1% per year) when used consistently and correctly: implants, injectable or patch hormonal contraception, oral contraceptives, IUD, double-barrier contraception, sexual abstinence. The form of birth control will be documented at screening and baseline.
10. Participants must be US citizens.
Exclusion Criteria:
1. Female of childbearing potential who is not willing to use one of the specified forms of birth control during the study.
2. Female that is pregnant or breastfeeding.
3. Claustrophobic.
4. History of a neurological disorder (i.e. Parkinson's, epilepsy, dementia, etc.) excluding sequelae of traumatic injury.
5. In the judgment of the investigator, the subject is at significant risk for suicidal behavior during the course of their participation in the study.
6. History of schizophrenia or schizoaffective disorders, or any history of psychotic symptoms.
7. Has a clinically significant abnormality on the screening physical examination that might affect safety, study participation, or confound interpretation of study results.
8. Participation in any clinical trial with an investigational drug or device within the past month or concurrent to study participation.
9. Any current or past history of any physical condition which in the investigator's opinion might put the subject at risk or interfere with study results interpretation.
10. Any history of cardiovascular problems.
11. Any history of liver or kidney problems.