A Comparison Of Plasma 5-HT Level In Childhood Autism Patients And Normal Controls

ObjectiveThe purpose of this study was to explore the pathophysiological mechanism of childhood autism determined by the level of serotonin (5-HT) in plasma , and explore the relationship between the level of 5-HT in plasma and the characteristics of autism . MethodsPlasma levels of 5-HT were measured with radiational immunization assay (RIA) in 54 patients with childhood autism and compared with those in 26 healthy controls .Childhood Autism Rating Scale ( CARS ) was administered to assess the severity of the disease . The score below 36 was mild-medium degree ; while the score above or equal to 36 , was severe degree . Resultsl.Plasma level of 5-HT was significantly higher in autism patients (161.19 119.02ug/ml) than that in controls (76.39 71.37ug/ml) ( t=3.961, P0.001 ) .2.No significant difference was found in the 5-HT level between the subgroups with different CARS scores ( mild-medium: 129.08 89.89 ug/ml, severe : 171.37 126.11 ug/ml, t=1.119,P>0.05 ) .3.There was no significant correlation between the level of 5-HT and the total scores of CARS ( r=0.157,P>0.05 ) .4.There was a significant positive correlation between the level of 5-HT and the "near" sense response ( r=0.367, P<0.01 ) .5.There was no significant correlation between the level of 5-HT and the age of the patients ( r=-0.007, P>0.05 ) .6.There was no significant correlation between the level of 5-HT and theduration of the disease ( r=-0.032, P>0.05 ) .7.There was no significant correlation between the level of 5-HT and the intellectual functioning ( r=0.019, P>0.05 ) .Conclusion1. Plasma level of 5-HT was significantly higher in autism than that in controls. Hyperserotonin may be a kind of biochemistric trait in a subgroup of childhood autism.2. Plasma level of 5-HT had influence on the near sense response .3. Plasma level of 5-HT neither affected the the severity of autism, nor had correlation with the age, gender and the duration of the disease .4. Plasma level of 5-HT had no correlation with the cognitive impairment.