title: Methylphenidate treatment and dyskinesia in children with attention-deficit/hyperactivity disorder.
abstract: OBJECTIVE
  Case reports suggest a relationship between methylphenidate treatment and dyskinesia in attention-deficit/hyperactivity disorder (ADHD). The aim of the current study was (a) to investigate abnormal involuntary movements of children with ADHD before and after the administration of methylphenidate and (b) to investigate the effect of a provocative assessment method used to make latent dyskinesia visible, which is included in the Abnormal Involuntary Movement Scale (AIMS).
  
  
  METHODS
  Participants, aged 6-18, were recruited from a Child and Adolescent Psychiatric Hospital and Outpatient Clinic (Vadaskert Foundation), Budapest, Hungary. Using a structured diagnostic interview (Mini International Neuropsychiatric Interview Kid), 37 children were included in the ADHD group and 34 children in the control group. The AIMS was used to observe and score dyskinesia.
  
  
  RESULTS
  There was a significant difference between the baseline total AIMS score in the ADHD and the control groups, with the ADHD subjects evidencing substantially higher severity than controls. Provocation, as applied with the administration of the AIMS, significantly increased the AIMS total score in both groups. The administration of methylphenidate had no effect on the total score of the AIMS. In the ADHD group, we observed a significant negative relationship between the patients' age and the overall severity on the AIMS. In contrast, in the control group we detected a significant positive relationship between the patients' age and the overall severity on the AIMS before and no relationship after provocation.
  
  
  CONCLUSIONS
  Methylphenidate-treated children with ADHD had more dyskinesia than children in the control group. Dyskinesia did not worsen after a single dose of methylphenidate. Higher dyskinesia scores in the methylphenidate-treated younger age group warrant caution in the methylphenidate treatment of ADHD; however, further studies are needed to clarify the possible causal relationship between dyskinesia and methylphenidate treatment and/or age and/or the disease itself.
authors.affiliation: Vadaskert Foundation, Child and Adolescent Psychiatry Hospital and Outpatient Clinic, Institute of Psychology, Eötvös Loránd University, Budapest, Hungary. judit.agnes.balazs@gmail.com
authors.forename: Judit
authors.initials: J
authors.lastname: Balázs
authors.forename: Gyöngyvér
authors.initials: G
authors.lastname: Dallos
authors.forename: Agnes
authors.initials: A
authors.lastname: Keresztény
authors.forename: Pál
authors.initials: P
authors.lastname: Czobor
authors.forename: Júlia
authors.initials: J
authors.lastname: Gádoros
mesh_terms: D000293:Adolescent; D001288:Attention; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D000697:Central Nervous System Stimulants / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D020820:Dyskinesias / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006814:Hungary; D007406:Interview, Psychological; D008297:Male; D008774:Methylphenidate / Q000009:adverse effects / Q000627:therapeutic use*; D011569:Psychiatric Status Rating Scales
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate