title: Dopamine D4 receptors: beyond schizophrenia.
abstract: Dopamine D4 receptors mediate a wide range of neuronal signal transduction cascades. Malfunctions of these mechanisms may contribute to the pathophysiology of neuropsychiatric disorders, and their modification underlies the actions of many psychotropic drugs. Postmortem neuropathological and genetic studies provide inconclusive associations between D4 receptors and schizophrenia. Clinical trials of partially selective lead D4 antagonists have proved them to be ineffective against psychotic symptoms in patients diagnosed with schizophrenia. However, associations are emerging between D4 receptors and other neuropsychiatric disorders, including attention-deficit hyperactivity disorder as well as specific personality traits such as novelty seeking. Preclinical studies indicate that D4 receptors play a pivotal role in the cellular mechanisms of hyperactivity, impulsivity, and working memory. Accordingly, D4 receptors have broader implications for human illnesses than has been suggested by early focus on psychotic illness as a clinical target, and selective D4 agents may yield clinically useful drugs for several neuropsychiatric disorders that require improved treatments.
authors.affiliation: Mailman Research Center, McLean Division of Massachusetts General Hospital, Belmont, Massachusetts, USA. ftarazi@hms.harvard.edu
authors.forename: Frank I
authors.initials: FI
authors.lastname: Tarazi
authors.forename: Kehong
authors.initials: K
authors.lastname: Zhang
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Baldessarini
mesh_terms: D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology; D001289:Attention Deficit Disorder with Hyperactivity / Q000235:genetics / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D002986:Clinical Trials as Topic; D065127:Dopamine D2 Receptor Antagonists; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050638:Receptors, Dopamine D4; D012559:Schizophrenia / Q000209:etiology / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014018:Tissue Distribution
chemical_list: D014150:Antipsychotic Agents; C493599:DRD4 protein, human; D065127:Dopamine D2 Receptor Antagonists; C493600:Drd4 protein, mouse; D012333:RNA, Messenger; D017448:Receptors, Dopamine D2; D050638:Receptors, Dopamine D4