title: A randomized, double-blind, crossover comparison of MK-0929 and placebo in the treatment of adults with ADHD.
abstract: OBJECTIVE
  Preclinical models, receptor localization, and genetic linkage data support the role of D4 receptors in the etiology of ADHD. This proof-of-concept study was designed to evaluate MK-0929, a selective D4 receptor antagonist as treatment for adult ADHD.
  
  
  METHODS
  A randomized, double-blind, placebo-controlled, crossover study was conducted in adults with primary ADHD. The primary end point was changed from baseline in total score on the Adult ADHD Investigator Symptom Rating Scale following a 4-week treatment regimen. Additional measures included Clinical Global Impression-Severity Scale, Hospital Anxiety and Depression Scale, and Brown Attention Deficit Disorder Scale and D4 genotype analysis.
  
  
  RESULTS
  No statistically significant treatment differences were found between MK-0929 and placebo in any of the primary or secondary assessments.
  
  
  CONCLUSIONS
  Results from this study suggest that blockade of the D4 receptor alone is not efficacious in the treatment of adult ADHD.
authors.affiliation: Merck Research Laboratories, North Wales, PA 19486, USA. anna_rivkin@merck.com
authors.forename: Anna
authors.initials: A
authors.lastname: Rivkin
authors.forename: Robert C
authors.initials: RC
authors.lastname: Alexander
authors.forename: Jennifer
authors.initials: J
authors.lastname: Knighton
authors.forename: Pete H
authors.initials: PH
authors.lastname: Hutson
authors.forename: Xiaojing J
authors.initials: XJ
authors.lastname: Wang
authors.forename: Duane B
authors.initials: DB
authors.lastname: Snavely
authors.forename: Thomas
authors.initials: T
authors.lastname: Rosah
authors.forename: Alan P
authors.initials: AP
authors.lastname: Watt
authors.forename: Fred W
authors.initials: FW
authors.lastname: Reimherr
authors.forename: Lenard A
authors.initials: LA
authors.lastname: Adler
mesh_terms: D000293:Adolescent; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy*; D018592:Cross-Over Studies; D018492:Dopamine Antagonists / Q000494:pharmacology / Q000627:therapeutic use*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D018492:Dopamine Antagonists