title: Plasma levels of serotonin, gastrointestinal symptoms,and sleep problems in children with autism.
abstract: OBJECTIVE
  Autism is a neurodevelopmental disorder identified with higher frequency of serotonin abnormalities and gastrointestinal (GI) and sleep problems. This study aimed to evaluate the plasma levels of serotonin, GI symptoms, and sleep problems, and their relationship with autism severity in children with autism.
  
  
  METHODS
  Thirty-five children with autism and 31 healthy subjects were studied. GI problems, sleep disorders, and severity of disorder were assessed. Plasma serotonin was determined using ELISA.
  
  
  RESULTS
  There was no significant association between GI problems and autism severity, but a significant positive correlation was seen between different indicators of sleep disorder and severity of autism. Plasma levels of serotonin were significantly higher in autistic children and a significant negative correlation was observed between plasma levels of serotonin and autism severity (r = -0.39, P = 0.02).
  
  
  CONCLUSIONS
  Elevated plasma serotonin in autistic children and its negative correlation with disease severity may indicate involvement of the neurotransmitter in the neurophysiologic mechanism of autism.
authors.affiliation: Department of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Sorayya
authors.initials: S
authors.lastname: Kheirouri
authors.affiliation: Department of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Parinaz
authors.initials: P
authors.lastname: Kalejahi
authors.affiliation: Research Center of Psychiatry and Behavioral Sciences (RCPBS), Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Seyyed Gholamreza
authors.initials: SG
authors.lastname: Noorazar
mesh_terms: D001321:Autistic Disorder; D002648:Child; D005767:Gastrointestinal Diseases; D006801:Humans; D012701:Serotonin
chemical_list: D012701:Serotonin
keywords: Autism; autism severity; gastrointestinal symptoms; serotonin; sleep problems