The role of phenotypes (diagnoses) in genetic studies of attention-deficit/hyperactivity disorder and related child psychopathology

The new medical genetics and its molecular, population, and statistical tec hniques offer a cadre of tools that will improve the child psychiatrist's a bility to diagnose and treat children who exhibit emotional and behavioral disorders. To take advantage of these remarkable advances, child psychiatry must enhance the likelihood that scientific expeditions into gene discover y are informed by a taxonomy that meets the criteria of a genetic nosology. As the taxonomic approach is refined, there may be more success in identif ying genetic and environmental risks for attention-deficit/hyperactivity di sorder (ADHD).