 Attention deficit and hyperactivity disorder, or ADHD, is the most common neuropsychiatric disorder of childhood. About 1 in 10 kids here in Montgomery County are diagnosed with a disorder, and 1 in 15 take psychostimulants as a treatment. Now what many people don't know is that about 30% of those kids are still going to have ADHD as adults. And those adults usually suffer of lower educational and working achievements. Now one of the issues is that ADHD is currently diagnosed using a clinical interview. In our lab, we aim to quantify ADHD using genetics and neural data, and this way have a better understanding of the disorder. But what kind of martyrs are we looking for? Well, we know that ADHD is highly heritable. We also know that ADHD involves different systems in the brain. So here we ask what connections in the brain are both heritable and associated with symptoms of ADHD. The brain imaging that we're going to be using is called diffusion tractography imaging, or DTI. DTI uses property of water diffusion to infer the orientation of different connections in the brain. These connections are called white fiber tracts. So think of a brain image as different 3D cubes, and within each of these cubes, we're going to estimate the orientation, and that's the different colors in the figure, of the different connections. Then based on this orientation, we're going to group the different fiber tracts into 11 major tracts. That's what we show here in the lateral view of the brain. For each of these 11 major tracts, we're going to estimate two properties. So think of these connections as a water hose. Water in a hose can flow along the axis of the hose, so that would be the axial diffusivity, or along the radius of the hose, that would be the radial diffusivity. So for each of these 11 major tracts, we have these two different properties. Now in our findings, out of the 22 possible variables, 10 are highly heritable in ADHD. Out of these 10, 4 are also associated with symptoms of ADHD, and I show these tracts in the rotating brain. The fascinating thing is that these tracts connect regions that have been shown in the literature to be associated with ADHD. Also, another very important finding is that these results are restricted to the radial component. Now people have shown in the literature that the radial component is related to myelin. Myelin is an insulating sheet in these connections, and it's crucial for proper functioning of the nervous system. So we see that these different properties, the RD property, could be a potential target for future genomic studies.