Genetic Epidemiology of ADHD

Washington University, Saint Louis MO

Investigators

Linked publications & trials

Abstract

This is a resubmission of an application requesting 4 years of continued funding for grant 1R01MH52813 (Genetic Epidemiology of ADHD). The long-term research goal of this project continues to be the identification of genetics factors which predispose to the development and course of attention deficit/hyperactivity disorder (ADHD). The immediate goal of the current application is to test the discriminant validity of DSM-IV and latent class conceptualizations of ADHD subtypes on the stability, course and outcome of illness. During the initial funding period of this project we have developed an alternative DSM-IV nosology using latent class analysis. In contrast to DSM-IV ADHD subtypes, these new phenotypes appear to be genetically independent forms of ADHD. These studies utilized birth defects based identification of twins with ADHD symptomatology through a two-stage screening process. In this current application we propose to conduct a 5- year follow-up study of 450 families identified through having a latent class or DSM-IV identified ADHD subtype. In addition to repeating the original evaluation assessment, families will also complete an enhanced set of interviews and questionnaires relating to family history, home environment and outcome measures. In combination with the epidemiologically based screening and interview results of the current study, these prospective re-evaluations will be analyzed using a combination of latent class, logistic regression, and multi-variate genetic analyses using structural equation modeling. Our hypotheses are that latent class defined ADHD subtypes will be stable over time representing highly heritable independent forms of ADHD which are associated with specific patterns of cognitive, academic testing and educational deficits. Furthermore, we hypothesize that these patterns of disabilities and deficits will have differential effects on the initiation, use and abuse of psychoactive compounds such as alcohol and nicotine, on health care usage patterns and frequency of accidents. Given the results of the current funding period, we feel these analyses are likely to provide a new diagnostic formulation of ADHD syndromes which is more appropriate for identification of genetic and environmental factors influencing the etiology, course and disabilities associated with these syndromes.