Stanford Regulating Circuits of the Brain Study - MDMA

Inclusion Criteria:

   1. Ages 18-55

   2. Able to swallow capsules

   3. All genders and ethno-racial categories

   4. Able and willing to enroll and provide written informed consent.

   5. Able to comply with study procedures.

   6. 2+ prior uses of MDMA when aged 18 years or older and have reported no serious adverse
   reactions from MDMA or ecstasy.

   7. Non-nicotine user, defined as no primary nicotine exposure for last six months.

   8. Agree to not use caffeine for 12 hours before and 10 hours after drug administration.

   9. Not using any medication or substance that might increase the risk of participation
   and/or interact with MDMA (i.e., serotonergic agents, antidepressants, opiates, any
   drugs with known interactions with Monoamine Oxidase Inhibitors).

10. Must agree to inform the investigators within 48 hours of any changes in medical
   conditions or procedures.

11. If of childbearing potential, must have a negative pregnancy test at study entry and
   prior to each drug session and must agree to use adequate birth control through 10
   days after the last drug session. Adequate birth control methods include intrauterine
   device (IUD), injected or implanted hormonal methods, abstinence, oral hormones plus a
   barrier contraception, vasectomized sole partner, or double barrier contraception. Two
   forms of contraception are required with any barrier method or oral hormones.

12. Able to receive an MRI.

Exclusion Criteria:

   1. Have current serious suicide risk, as determined through psychiatric interview,
   responses to C-SSRS, and clinical judgment of the investigator.

   2. Current psychiatric, mood, anxiety, eating or psychotic disorder assessed at screening
   with the MINI and medical history.

   3. Current use of any psychotropic medication (a wash-out period of 5 half-lives will be
   required prior to drug visits followed by a 1-week stabilization period, if the
   participant reports recently discontinuing a psychotropic medication).

   4. Have used Ecstasy (material represented as containing MDMA) within 6 months of the
   first study dose; or have previously participated in a MAPS-sponsored MDMA clinical
   trial; or have used Ecstasy (material represented as containing MDMA) more than 10
   times within the last 10 years.

   5. Positive for drug, or alcohol abuse disorders as assessed through DAST, CUDIT-R,
   Fagerstrom and AUDIT measures.

   6. Positive test on urine drug screen for illicit and/or drugs of abuse at screening and
   prior to study drug administration.

   7. Concurrent use of any medication or substance that might increase the risk of
   participation and/or interact with MDMA (i.e., serotonergic agents, antidepressants,
   opiates, any drugs with known interactions with Monoamine Oxidase Inhibitors).

   8. Unable or unwilling to agree to refrain from using any psychoactive substances (i.e.,
   cannabis), supplements (i.e., St. John's Wort, SAMe, 5HTP) and nonprescription
   medications (i.e., dextromethorphan) starting 1-week prior to study start and for
   duration of study.

   9. Current use of any opioids, including codeine, hydrocodone, and morphine.

10. Have an exclusionary metal device (e.g., presence of metallic device or dental braces,
   which are contraindications for MRI) as determined by the discretion of the Clinical
   Investigator.

11. BMI outside of healthy range (18-30)

12. Inability to speak, read or understand English at a 5th grade level or severe hearing
   impairment.

13. Plan to move out of the area during the study period (given repeated testing sessions)

14. Individuals who are pregnant or nursing.

15. Schizophrenia in a first degree relative.

16. Direct physical access to or routinely handling of addicting drugs in the regular
   course of work duties.

17. Allergy or hypersensitivity to MDMA

18. Renal/hepatic impairment (assessed via laboratory tests during initial screening
   appointment)

19. Hypertension (Hypertension, Stage 1 as defined by a systolic blood pressure >140 mmHg
   or diastolic blood pressure > 90 mmHg on two of three measurements at least 15 minutes
   apart at initial screening appointment; systolic blood pressure >155 mmHg or diastolic
   blood pressure >99 mmHg on two of three measurements at least 15 minutes apart during
   drug administration visits)

20. Heart rate <50bpm or >150bpm assessed at initial screening visit (PI discretion for
   bradycardia)

21. Chronic congestive heart failure, tachyarrhythmias, myocardial ischemia (assessed via
   EKG at initial screening appointment)

22. Have a marked Baseline prolongation of QT/QTc interval e.g., repeated demonstration of
   a QTc interval >450 milliseconds (ms) in males and >460 ms in females. For transgender
   or non-binary participants, QTc interval will be evaluated based on sex assigned at
   birth, unless the participant has been on hormonal treatment for 5 or more years.

23. Have evidence or history of significant (controlled or uncontrolled) hematological,
   endocrine, cerebrovascular, cardiovascular, coronary, pulmonary, renal,
   gastrointestinal, immunocompromising, or neurological disease, including seizure
   disorder, or any other medical disorder judged by the investigator to significantly
   increase the risk of MDMA administration (participants with hypothyroidism who are on
   adequate and stable thyroid replacement will not be excluded). Note: if participants
   present with a history of glaucoma, enrollment would be allowed only with the approval
   of their ophthalmologist.

24. Have a history of additional risk factors for Torsade de pointes (e.g., heart failure,
   hypokalemia, family history of Long QT Syndrome)

25. Have history of hyponatremia or hyperthermia