title: What do we know about the serotonergic genetic heterogeneity in attention-deficit/hyperactivity and autistic disorders?
abstract: BACKGROUND
  Shared candidate gene regions point to a link between autistic disorders and attention-deficit/hyperactivity disorder (ADHD). Although they represent nosologically different diagnoses, the disorders do show some shared symptoms, above all inattention. For both disorders, the association with the serotonergic system is a focus of current research.
  
  
  METHODS
  The current work provides an overview of serotonergic mechanisms in ADHD and autistic disorders as well as the resulting pharmacogenetic approaches.
  
  
  RESULTS
  No uniform picture emerges either for ADHD or for autistic disorders. In pharmacogenetic terms, there are some isolated studies on associations between serotonergic mechanisms and pharmacotherapy. For the area of autism, such studies are still lacking.
  
  
  CONCLUSIONS
  The presented serotonergic mechanisms show relationships of this polymorphism to ADHD and autistic disorders, but they do not result in a uniform picture. The overlaps can best be explained by a dimensional classification approach. As yet, only a small number of studies on attentional disorders in autism and ADHD using shared samples have been carried out. With regard to diagnostics and therapy, analyses on the etiology of the attentional disorder of ADHD and autism are required.
authors.affiliation: Clinic for Psychiatry and Psychotherapy in Childhood and Adolescence at the Clinical Center of the University of Cologne, Cologne, Germany. ju.k.sinzig@web.de
authors.forename: J
authors.initials: J
authors.lastname: Sinzig
authors.forename: G
authors.initials: G
authors.lastname: Lehmkuhl
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D001321:Autistic Disorder / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D002648:Child; D002886:Chromosomes, Human, Pair 17; D015897:Comorbidity; D005838:Genotype; D006801:Humans; D018598:Minisatellite Repeats / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins; D017367:Selective Serotonin Reuptake Inhibitors; C493230:SLC6A4 protein, human