The ADHD Clinical Research Program at Massachusetts General Hospital currently offers a range of protocols addressing different aspects of ADHD in children and adolescents. Although these protocols have received prior IRB approval, potential participants present with a widely varied set of complaints not always discernable in a telephone screening interview. This state of affairs often makes it difficult to ask subjects and their parents to sign a specific protocol's consent form without obtaining additional clinical information. Because of this, we are proposing that potential subjects and their parents undergo an in-depth clinical assessment that will allow them to be screened by a clinician for eligibility to a diverse clinical research program.