Attention Deficit Hyperactivity Disorder (ADHD)
What is Attention Deficit-Hyperactivity Disorder?
Attention Deficit-Hyperactivity Disorder (ADHD) is the most common developmental disorder of childhood, affecting 3-7% of children and often continuing into adulthood. ADHD has many deleterious long-term consequences such as increased risk for antisocial disorders, drug abuse, automobile accidents, and teenage pregnancy among others. Most researchers and clinicians assume that ADHD has a neurobiological etiology. This assumption is based largely upon multiple lines of evidence including the voluminous base of neuropsychological studies suggesting neuroanatomical dysfunction, ADHD patients' response to psychostimulant medication, and the multiple family, twin, and adoption studies that suggest a genetic basis to this disorder. New research technologies (e.g., fMRI) are allowing researchers to more specifically examine neuroanatomical abnormalities as they may be related to ADHD. To date, the volume of research using these advanced research procedures is minimal.
SPNL Study of ADHD
In the SPNL, our goals are to examine neuroanatomical and neurophysiological abnormalities in ADHD patients AND to examine the relations between these abnormalities and medication response. The unique strengths of the proposed study include the following: 1) The use of concordantly ADHD-affected parent-child dyads; 2) The use of the preexisting Multimodal Treatment Study of ADHD Children (MTA) sample for recruiting parent-child dyads; and 3) The use of multiple geographical sites for subject recruitment and data acquisition. Utilizing affected parent-child dyads should bias the sample towards ADHD patients with biological etiologies making neuropsychological and neuroanatomical abnormalities easier to detect. Utilizing the MTA sample allows for a readily-available sample with preexisting data on which to select parent-child dyads. Finally, the utilization of multiple geographical sites promotes a larger sample size and enhanced generalization of the study's findings. Specifically, our goals are to:
- Map ADHD neuropsychological performance deficits to brain structure and brain functioning using MRI technology.
- Examine functional neuroanatomical changes in response to stimulant medications.
- Describe familial aggregation of neuropsychological performance deficits, neuroanatomical abnormalities, and neurofunctional response to stimulant medication in ADHD parent-child dyads.
The proposed study is important for the following reasons:
- The proposed study meets a primary objective delineated in the "NIMH Strategic Plan." Goal 1 of this plan calls for increasing our understanding of the contribution of developmental processes to brain and behavior and mental disorders and understanding brain function and how these go awry in mental illness. This proposed study is an important step in accomplishing this objective in regards to ADHD.
- The proposed study directly addresses a call for future research in the NIH Consensus Development Conference on Diagnosis and Treatment of ADHD. Specifically, the final Consensus Statement begins by stating that there is a clear need for more basic research to better define ADHD and that there is a specific need for further brain imaging studies that examine ADHD deficits throughout the life span.
- The proposed study is consistent with a recently issued NIMH Program Announcement entitled "Basic and Applied Research Related to ADHD" (PA-01-083). One of the stated goals of this program announcement is to "encourage basic behavioral and neuroscience research in dimensions of attention and inhibitory control" in ADHD patients.