Platelet vesicular monoamine transporter 2 density in the disruptive behavior disorders

In a former study, we reported decreased platelet vesicular monoamine transporter 2 (VMAT2) density (Bmax) in patients with ADHD. The current study aimed at measuring platelet VMAT2 in the disruptive behavior disorders (DBDs) to assess whether this finding is specific to ADHD or generalizable to the broader DBD concept. The study included 13 patients with DBDs aged 10-12 years and 16 healthy volunteers aged 8-17 years. All participants underwent a thorough clinical evaluation using Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime version for diagnosis, the Nisonger Child Behavior Rating Form, the Clinical Global Impressions Scale-Severity version, and the DSM-IV ADHD Scale (DAS). The study group's DAS scores did not differ from those of the control group. There was no significant difference between the patients with DBDs and the control group either in VMAT2 density (Bmax) or affinity (Kd) as measured by high-affinity [(3)H]TBZOH binding. We conclude that the formerly reported decreased platelet VMAT2 Bmax in patients with ADHD may be specific to ADHD and not present in DBDs. Larger-scale replication is needed.