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

This study will test the effectiveness of lisdexamfetamine medication as a treatment for loss-of-control eating and weight following bariatric surgery. This is a controlled test of whether, amongst non-responders to acute treatments, lisdexamfetamine medication results in superior outcomes compared with placebo.

Inclusion Criteria: * Be in the age range ≥18 years of age and \ 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