Attention-deficit/hyperactivity disorder (ADHD) is a condition characterized by attention difficulty, hyperactivity, and impulsiveness. The treatment of ADHD has been long focused on the dopaminergic system’s contribution to pathogenesis, but recent studies also indicate the involvement of the noradrenergic system. The objective of this study is to evaluate the norepinephrine transporter (NET) nondisplaceable binding potential (NET BPnd) using positron emission tomography.
This study included a total of 22 medication-free patients with ADHD without psychiatric comorbidities (mean age 30.7 years, 68% men), along with 22 age- and sex-matched healthy controls. All the participants underwent positron emission tomography once, and the primary outcome was the NET BPnd in the selected regions of interest, including the thalamus, midbrain with pons, putamen, pallidum, and hippocampus.
The findings indicated no difference in NET availability or regional distribution between patients with ADHD and healthy controls. Besides, no significant associations were found between ADHD symptom severity and regional NET availability. There was a negative correlation between age and NET availability in the thalamus and midbrain with pons.
The research concluded that there were no substantial differences between NET availability or region distribution between patients with ADHD and healthy controls. In addition, there was no correlation between ADHD symptom severity and regional net availability.