Magnetic resonance imaging measurement of the caudate nucleus in adolescents with attention-deficit hyperactivity disorder and its relationship with neuropsychological and behavioral measures

Objective: To investigate structural basal ganglia abnormalities in attention-deficit hyperactivity disorder (ADHD) and their relationship with the neuropsychological deficits and behavioral problems found in ADHD. Design: Case-control study. Setting: Adolescents were recruited from a local polytechnic institute of secondary education. Subjects: Eleven adolescents with ADHD and 19 healthy control subjects. Subjects with ADHD were diagnosed by the school psychologist from a total population of 450 students according to the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised. Diagnosis was confirmed by the Conners Teachers Rating Scale and a structured family interview. Main Outcome Measures: Magnetic resonance imaging single-slice transversal measurements of the head of the caudate nucleus and a comprehensive neuropsychological evaluation, which was specially designed to assess frontal-striatal functioning. Results: The ADHD group had a larger right caudate nucleus area than the control group. In control adolescents, larger caudate nucleus areas were associated with poorer performance on tests of attention and higher ratings on the Conners Teachers Rating Scale. Conclusions: These findings provide further evidence of the involvement of the caudate nucleus in the neuropsychological deficits and behavioral problems found in ADHD. The larger caudate nucleus found in the ADHD group could be related to a failure of the maturational processes that normally result in volume reduction.