Introduction: Certain behaviors associated with high intellectual ability, such as inattention and early response, are often confused with attention deficit and hyperactivity disorder (ADHD), making correct diagnosis more difficult. The objective of the present study was to analyze the performance of students with high intellectual ability and…

Objective: A previous factor analysis of the Conners' Continuous Performance Test (CCPT) indicates that the test measures 5 sub-functions of attention, namely "focused attention," "hyperactivity/impulsivity," "sustained attention," "vigilance," and "change in control." The present study further…

The Predominantly Inattentive (PI) and Combined (CB) subtypes of AD/HD differ in cognitive tempo, age of onset, gender ratio, and comorbidity, yet a differentiating endophenotype has not been identified. The aim of this study was to test rigorously diagnosed PI, CB, and typical children on measures selected for their potential to reveal…

Seven different laboratory measures of impulsivity were administered to a group of 165 school-aged boys. Parents' and teachers' ratings of Attention Deficit and Hyperactivity Disorder and Oppositional/Defiant Disorder were also obtained. Factor analyses of impulsivity measures revealed the existence of a strong Inhibitory Control Factor including…

Adolescents with substance use and conduct disorders have high rates of aggression and attention deficit hyperactivity disorder (ADHD), all of which have been characterized in part by impulsivity. Developing measures that capture impulsivity behaviorally and correlate with self-reported impulsivity has been difficult. One promising behavioral…

Objective: The purpose of this study was to assess heritability of activity, attention, and impulsivity by comparing young monozygotic (MZ) twins with dizygotic (DZ) twins using objective measures. Method: The OPTAx test is an infrared motion analysis to record the movement pattern during a continuous performance test. Seventeen MZ and 12 same…