title: Performance and private speech of children with attention-deficit/hyperactivity disorder while taking the Tower of Hanoi test: effects of depth of search, diagnostic subtype, and methylphenidate.
abstract: We administered the Tower of Hanoi to demographically comparable samples of control participants (n = 34) and children with the Combined (n = 22) and Inattentive subtypes (n = 19) of Attention-Deficit/Hyperactivity Disorder (ADHD). Controls excelled over children with the Inattentive subtype, who outperformed patients with the Combined subtype. These results replicated findings of greater executive deficits in the Combined than in the Inattentive type of ADHD. Double-blind administration of methylphenidate improved task performance only for patients with the Inattentive subtype. In a drug-free Baseline session, children with both subtypes of ADHD made more private verbalizations than controls, particularly when failing puzzles. In later sessions, regardless of drug condition, the inattentive sample exhibited a smaller increase in self-regulatory utterances under failure. In contrast, the combined sample decreased self-regulatory verbalizations under failure only under methylphenidate. The results support some differences between the two subtypes of ADHD in executive functioning and in their response to stimulant therapy.
authors.affiliation: Department of Clinical and Social Sciences in Psychology, University of Rochester, RC Box 270266, Meliora Hall, Rochester, NY 14627-0266, USA.
authors.forename: Helena
authors.initials: H
authors.lastname: Kopecky
authors.forename: H Theresa
authors.initials: HT
authors.lastname: Chang
authors.forename: Rafael
authors.initials: R
authors.lastname: Klorman
authors.forename: Joan E
authors.initials: JE
authors.lastname: Thatcher
authors.forename: Agneta D
authors.initials: AD
authors.lastname: Borgstedt
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000188:drug therapy*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002648:Child; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D009483:Neuropsychological Tests; D013060:Speech; D014705:Verbal Behavior
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate