Original articlesReduced midbrain dopamine transporter binding in male adolescents with attention-deficit/hyperactivity disorder: Association between striatal dopamine markers and motor hyperactivity
Section snippets
Subjects
The study was approved by the Research Ethics and Radiation Safety Committees of the Karolinska Hospital. Participation in the study was voluntary, and the subjects agreed to participate after receiving written and oral information. Written informed consent was obtained from the subjects and/or their parents in accordance with the Declaration of Helsinki. The study was carried out at the PET Centre, Department of Clinical Neuroscience, Karolinska Institutet (Stockholm, Sweden).
The comparison
Dopamine transporter binding
In all subjects, the [11C]PE2I binding was highest in the striatum (caudate nucleus and putamen), lower in the midbrain (substantia nigra/ventral tegmentum), and lowest in the cerebellum (Figure 1, Figure 2). In this limited series of subjects covering a narrow age range, no significant age effect was found for [11C]PE2I binding in the striatum in any of the groups. There was, however, a tendency for DAT binding in the caudate nucleus to decrease in the adult group (regression coefficient R =
Discussion
The main results of this PET study were as follows: 1) no support for an increase in the DAT or D2R marker density in the striatum of adolescents with ADHD; 2) lower binding to DAT in the midbrain of adolescents with ADHD; and 3) statistically significant correlations between DAT and D2R binding in the striatum and measures of hyperactivity.
The mean DAT and D2R binding potential in the striatum of adolescents with ADHD was 4% and 6% higher, respectively, than the corresponding values for young
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