Pharmacological and Behavioral Treatment After Bariatric Surgery: Medication Change for Non-Responders (Stage 2b)

Inclusion Criteria: * Be in the age range ≥18 years of age and \<65 years of age. * Have had laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy * Approximately ten months post-surgery * Experienced regular loss of control eating about six months after bariatric surgery, and were considered treatment non-responders to a four-month treatment trial of medication and/or BWL * Be an otherwise healthy subject without uncontrolled medical problems, as determined by the study physician and medical co-investigators (physical examination, laboratory studies). * Read, comprehend, and write English at a sufficient level to complete study-related materials. * Provide a signed and dated written informed consent prior to study participation. * Be available for participation in the study for up to 15 months (3-month treatment plus 12-month follow up). Exclusion Criteria: * Has a predisposition to seizures (e.g., subject with a history or evidence of seizure disorder, febrile seizures during childhood, brain tumor, cerebrovascular disease, or significant head trauma; has a family history of idiopathic seizure disorder or is currently being treated with medications or treatment regimens that lower seizure threshold). * Has a history of anorexia nervosa or history of bulimia nervosa. * Is currently using other medications for weight loss. * Has a co-existing psychiatric condition that requires hospitalization or more intensive treatment (such as bipolar mood disorders, psychotic illnesses, or severe depression) * Has untreated hypertension with a seated systolic blood pressure \> 160 mmHg, diastolic blood pressure \> 100 mmHg, or heart rate \> 100 beats/minute. * Has a history of congenital heart disease, cardiovascular disease, cardiac arrhythmias requiring medication, or a history of cerebrovascular pathology including stroke. * Has current uncontrolled hypertension. * Has current uncontrolled Type I or Type II diabetes mellitus. * Has untreated hypothyroidism with a TSH \> 1.5 times the upper limit of normal for the test laboratory with repeat value that also exceeds this limit. * Has gallbladder disease. * Has a history of severe renal, hepatic, neurological, chronic pulmonary disease, or any other unstable medical disorder. * Is currently in active treatment for eating or weight loss. * Is currently participating in another clinical study in which the subject is or will be exposed to an investigational or a non-investigational drug or device. * Is breast-feeding or is pregnant or is not using a reliable form of birth control. * Reports active suicidal or homicidal ideation. * Previous history of problems with LDX or other stimulants. * Has a history of allergy or sensitivity to LDX or other stimulant medications. * Current medication contraindicated with study medication. * Any current psychostimulant use or any medication for ADHD. * History or current alcohol or substance use disorder (smoking will not be exclusionary) * Is currently taking MAOI medication, SSRI medication, or strong inhibitors of CYP2D6