Serotonin uptake in platelets from child neuropsychiatric patients

Serotonin uptake abnormalities have been widely described in depressed adult patients. However, few studies analyzed this peripheral marker of serotonergic system in child neuropsychiatric disorders, despite the clinical use of serotonin uptake inhibitors in these syndromes. In this preliminary study, we investigated possible modifications of serotonin uptake in platelets from 34 child neuropsychiatric patients, aged 7-16, devided, according to the ICD-10 classification, into the following cathegories: Attention Deficit Hyperactivity Disorder (ADHD), child autism, anxious syndromes, dysthymia. 10 normal age and sex related children were used as controls. Serotonin uptake was determined in fresh platelet preparations, using [H-3]serotonin, according to the method of Arora and Meltzer. Platelet serotonin uptake was decreased by 60% (p<0.01), respect to controls, both in ADHD and dysthymic patients, while it was unchanged in anxious syndromes and slightly decreased in autistic disorder. Anxiety, depression and behavioral scales were applied. Possible correlations between uptake changes and behavioral scales have been investigated. The similar decrease of serotonin uptake in children with affective disorders and ADHD suggests common biological mechanisms and explains the efficacy of uptake inhibitors in these syndromes.