• To improve diagnosis of ADHD children and adults using a multidimensional approach consisting of neurobiological and neurocognitive methods in conjunction with standard clinical tools;
• To identify neurobiological/neurocognitive subtypes within the population of DSM IV diagnosed ADHD patients toward a better understanding of the neuro-pathophysiology of ADHD;
• To optimize individual treatment through use of such multidimensional methods;
• To identify the evolution of each subtype of ADHD across the life span and the relationship of subtypes to this process;
• To describe the endophenotypes within ADHD population

Methodological Goals:

• To apply consistent diagnostic criteria for inclusion/exclusion in the study;
• Use of standardized protocol for clinical, behavioral, neuropsychological and electrophysiological data acquisition;
• Standardization of data formats for the multi-site exchange of data and building of an overall study database;
• Recruit a population of patients for sufficient statistical power will be required, not less than 500;
• Use multivariate statistical methods to the identification of subtypes across the entire population;
• Each site will also work independently toward the statistical identification of the endophenotypes using data from all sites;
• Each site will use the study core protocol, but are free to add additional measures to be collected at their site.