We are conducting a research study on how insulin controls blood sugar in both healthy people and those at risk of type 2 diabetes. We are seeking adult volunteers, aged 18-65, who have body mass indices either in the lean range (18-25 kg/m2) or in the obesity range (30-45 kg/m2) but who do not have prediabetes or diabetes. Participants will undergo a…
We're conducting a research study on how much insulin is needed to control blood sugar in people who are made temporarily resistant to insulin's effects. Insulin is the main hormone (chemical signal) that the body uses to lower the levels of sugar in the blood. We are interested in looking at insulin levels because we think that lowering insulin…
In this study, we are trying to learn more about how stimulant medication produces an improvement in emotional lability (frequent mood changes and excessive emotional reactions) in patients with Attention Deficit Hyperactivity Disorder (ADHD.) Although ADHD is primarily associated with inattention, hyperactivity, and impulsivity, emotional ability plays a…
Children with Attention-Deficit/Hyperactivity Disorder (ADHD) are typically treated with two types of medications: stimulants and non-stimulants. These medications work in different ways to treat ADHD symptoms, but we do not fully understand the brain mechanisms underlying the medications' effects. This study will use MRI scanning to look at changes in…