A Multi-Site Study of MDMA-Assisted Psychotherapy for Eating Disorders

Inclusion Criteria for Eating Disorder (ED) Participants: * Are 21 to 65 years old. * Are assigned female at birth. * Are fluent in speaking and reading the English language and can provide written informed consent. * Are able to swallow pills. * Agree to have study visits recorded to audio and video. * Are willing to include a consenting caregiver as a co-participant in elements of the study with whom the study team will have regular contact. This person must be willing and able to be reached by the investigators in case of emergency. * If connected to a psychotherapist at the time of recruitment into the study, participants may not change therapists, change the frequency of therapy, or commence any new type of therapy until after the Study Termination Visit, 1 month after the final Experimental Session. * Have an identified Primary Care Physician (PCP) and provide consent for the investigator to communicate with PCP, as needed. * If AN-R diagnosis, are currently participating in a recognized ED treatment program. * Are willing to sign a release for the investigators to communicate directly with their therapist, physician if relevant, as well treatment providers where they were currently or previously engaged an ED-specific episode of treatment. * Live within reasonable driving distance of the study site (equal to or less than an estimated 2-hour drive from the study site). * If of childbearing potential, must have a negative pregnancy test at study entry and prior to each Experimental Session, and must agree to use adequate birth control * Agree to inform the investigators within 48 hours of any medical conditions and procedures. * Agree to lifestyle modifications, comply with requirements for fasting and refraining from certain medications prior to Experimental Sessions, not participate in any other interventional clinical trials during the duration of the study, remain overnight at the study site (or appropriate location approved by the research team) after each Experimental Session, not operate a vehicle within 24 hours after MDMA administration, and commit to medication dosing, therapy, and study procedures. * Have Anorexia Nervosa, Restricting Type or Binge Eating Disorder. * Current or past treatment were not successful to retain remission * Have a BMI \> 15 kg/m2 and are medically stable according to screening Electrocardiogram (ECG), blood pressure monitoring, and blood and urine laboratory screening results. Exclusion Criteria for Eating Disorder (ED) Participants: * Are not able to give adequate informed consent. * Have any current problem which, in the opinion of the investigator or Medical Monitor, might interfere with participation. * Cannot identify a supportive caregiver to participate in the study (or the caregiver does not meet eligibility criteria). * Have a blood or needle phobia that interferes with obtaining necessary blood work * Have a history of significant medical disorders * Have any current problematic patterns of alcohol or other substance use * Require use of prohibited concomitant medications for this study, including those that prolong the QT/QTc interval during Experimental Sessions. * Have a history of any medical condition that could make receiving a sympathomimetic drug harmful because of increases in blood pressure and heart rate. * Have uncontrolled hypertension or history of ventricular arrhythmia. * Have Wolff-Parkinson-White syndrome or any other accessory pathway. * Have a marked Baseline prolongation of QTcF interval (e.g., repeated demonstration of a QTcF interval \> 450 ms). * Have a history of additional risk factors for Torsade de pointes (e.g., heart failure, hypokalemia, family history of Long QT Syndrome). * Have symptomatic liver disease. * Have a history of non-ED-symptom-related hyponatremia or hyperthermia. * Are pregnant or nursing, or are persons of childbearing potential who are not practicing (or not willing to practice) an effective means of birth control. * Are assessed to be medically unstable Inclusion Criteria for Caregiver (CG) Participants: * Are fluent in speaking and reading the English language and can provide written informed consent. * Are at least 18 years old. * Are the parent, partner, or other significant caregiver of the ED Participant. * Are involved in caregiving at least 2 hours a week (i.e. companionship, meal support, emotional support, driving to appointments, financial support, etc.). * Are willing to provide their loved one with meal/symptom support and emotional support throughout the study. * Live within reasonable driving distance of the study site * If in ongoing psychotherapy at the time participants are recruited into the study, caregiver participants may continue to see their outside therapist during the course of the study. Caregiver participants must sign a release for the investigators to communicate directly with their therapist. CG Participants may not change therapists, increase the frequency of therapy, or commence any new type of therapy until after their Study Termination Visit. * Are willing to commit to Preparatory and Integrative Sessions, completion of evaluation instruments and other study procedures, and being contacted for all necessary telephone contacts. * Agree to have study visits recorded to audio and video. Exclusion Criteria for Caregiver (CG) Participants: * Have a current eating disorder. * Are unable to give adequate informed consent. * Report any current problem which in the opinion of the investigator or Medical Monitor might interfere with enrollment or ongoing participation.