Platelet uptake of serotonin in psychotic children

Platelet serotonin (5-HT) uptake was assayed in ten long-term hospitalized children subdivided into two diagnostic groups "autistic" and "other psychotic". Weekly blood samples were taken from these children over a period of 6-7 weeks and serotonin uptake was determined. Constant and significant uptake values (13.28 +/- 2.0 pmol serotonin/10(8) platelets/5 min for autistics and 9.59 +/- 1.58 pmol serotonin/10(8) platelets/5 min for other psychotics) were obtained. There was no correlation with drug treatment or with behavioral fluctuations in individual children. Three weekly uptake assays performed on six parents suggest the possible importance of genetic factors in these diseases. Biochemical-kinetic methodological problems of platelet 5-HT assessment are discussed.