Striatal dopamine transporter density in drug naive patients with attention-deficit/hyperactivity disorder

Background and aim Dopamine transporters are the target of psychostimulants used for treatment of attention-deficit/hyperactivity disorder (ADHD). Therefore, the present study aimed to evaluate striatal dopamine transporter density in adult patients with ADHD. Methods Twenty patients (11 female, nine male; mean age 35 7 years) and 20 control subjects (11 female, nine male, mean age 32 +/- 8 years) were examined with SPECT using the specific radiotracer I-123-FP-CIT. The ratio of striatal to cortical radioactivity concentration was used for semiquantitative evaluation of dopamine transporter binding potential (V-3). There was a significant influence of age (P < 0.001) and a trend towards an influence of gender (P = 0.053) on V-3. An ANCOVA with these covariates showed a slightly higher V-3 in the patients than in the control subjects (4.24 +/- 0.48 vs. 4.03 +/- 0.56; P = 0.02). Conclusion This study provides further in-vivo evidence for an involvement of the dopamine transporter in ADHD. However, compared to previous studies, the increase of dopamine transporter density in the patient group is less pronounced here. Nucl Med Commun 27:267-270 @ 2006 Lippincott Williams & Wilkins.