title: Effects of short- and long-term risperidone treatment on prolactin levels in children with autism.
abstract: BACKGROUND
  The effects of short- and long-term risperidone treatment on serum prolactin were assessed in children and adolescents with autism.
  
  
  METHODS
  Patients with autism (N = 101, 5-17 years of age) were randomized to an 8-week trial of risperidone or placebo and 63 then took part in a 4-month open-label follow-up phase. Serum samples were obtained at Baseline and Week-8 (N = 78), and at 6-month (N = 43) and 22-month (N = 30) follow-up. Serum prolactin was determined by immunoradiometric assay; dopamine type-2 receptor (DRD2) polymorphisms were genotyped.
  
  
  RESULTS
  Baseline prolactin levels were similar in the risperidone (N = 42) and placebo (N = 36) groups (9.3 +/- 7.5 and 9.3 +/- 7.6 ng/ml, respectively). After 8 weeks of risperidone, prolactin increased to 39.0 +/- 19.2 ng/ml, compared with 10.1 +/- 8.8 ng/ml for placebo (p < .0001). Prolactin levels were also significantly increased at 6 months (32.4 +/- 17.8 ng/ml; N = 43, p < .0001) and at 22 months (N = 30, 25.3 +/- 15.6 ng/ml, p < .0001). Prolactin levels were not associated with adverse effects and DRD2 alleles (Taq1A, -141C Ins/Del, C957T) did not significantly influence baseline levels or risperidone-induced increases in prolactin.
  
  
  CONCLUSIONS
  Risperidone treatment was associated with two- to four-fold mean increases in serum prolactin in children with autism. Although risperidone-induced increases tended to diminish with time, further research on the consequences of long-term prolactin elevations in children and adolescents is needed.
authors.affiliation: Child Study Center, Yale University School of Medicine, New Haven, Connecticut, USA. george.anderson@yale.edu
authors.forename: George M
authors.initials: GM
authors.lastname: Anderson
authors.forename: Lawrence
authors.initials: L
authors.lastname: Scahill
authors.forename: James T
authors.initials: JT
authors.lastname: McCracken
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: McDougle
authors.forename: Michael G
authors.initials: MG
authors.lastname: Aman
authors.forename: Elaine
authors.initials: E
authors.lastname: Tierney
authors.forename: L Eugene
authors.initials: LE
authors.lastname: Arnold
authors.forename: Andrés
authors.initials: A
authors.lastname: Martin
authors.forename: Liliya
authors.initials: L
authors.lastname: Katsovich
authors.forename: David J
authors.initials: DJ
authors.lastname: Posey
authors.forename: Bhavik
authors.initials: B
authors.lastname: Shah
authors.forename: Benedetto
authors.initials: B
authors.lastname: Vitiello
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001321:Autistic Disorder / Q000097:blood* / Q000188:drug therapy* / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D011110:Polymorphism, Genetic; D011388:Prolactin / Q000097:blood*; D017448:Receptors, Dopamine D2 / Q000235:genetics; D018967:Risperidone / Q000627:therapeutic use*; D013997:Time Factors
chemical_list: D014150:Antipsychotic Agents; D017448:Receptors, Dopamine D2; D011388:Prolactin; D018967:Risperidone