title: Methylphenidate use and school performance among primary school children: a descriptive study.
abstract: There is no conclusive evidence that stimulants have beneficial effects on major associated outcome parameters, particularly school performance. We assessed the differences in school performance among children using methylphenidate at the end of primary school in relation to various parameters of methylphenidate use.
  
  
  
  We linked children from a pharmacy prescription database with standardized achievement test results at the end of primary school. We explored differences in test scores between current methylphenidate users versus never users and methylphenidate users who stopped treatment at least 6 months before the test, early versus late starters, different dosage of methylphenidate, and concurrent antipsychotic or asthma treatment.
  
  
  
  Out of the 7736 children, 377 (4.9%) children were treated with methylphenidate at the time of the test. After adjusting for confounders the methylphenidate users (532.58 ± .48) performed significantly lower on the test than never users (534.72 ± .11). Compared with late starters of methylphenidate treatment (536.94 ± 1.51) we found significantly lower test scores for the early starters (532.33 ± .50).
  
  
  
  Our study indicates that children using methylphenidate still perform less at school compared to their peers. Our study also suggests that earlier start of methylphenidate treatment is associated with a lower school performance compared to children starting later with the treatment. This result could either indicate a limited effect of long term treatment or a more strongly affected group of early starters.
authors.affiliation: Groningen Research Institute of Pharmacy, PharmacoTherapy, -Epidemiology & -Economics, University of Groningen, Antionius Deuginslaan 1, 9713 AV, Groningen, the Netherlands. J.van.der.schans@rug.nl.
authors.forename: Jurjen
authors.initials: J
authors.lastname: van der Schans
authors.affiliation: Groningen Research Institute of Pharmacy, PharmacoTherapy, -Epidemiology & -Economics, University of Groningen, Antionius Deuginslaan 1, 9713 AV, Groningen, the Netherlands.
authors.forename: Rukiye
authors.initials: R
authors.lastname: Çiçek
authors.affiliation: Groningen Research Institute of Pharmacy, PharmacoTherapy, -Epidemiology & -Economics, University of Groningen, Antionius Deuginslaan 1, 9713 AV, Groningen, the Netherlands.
authors.forename: Sefike
authors.initials: S
authors.lastname: Vardar
authors.affiliation: Groningen Research Institute of Pharmacy, PharmacoTherapy, -Epidemiology & -Economics, University of Groningen, Antionius Deuginslaan 1, 9713 AV, Groningen, the Netherlands.
authors.forename: Jens Hj
authors.initials: JH
authors.lastname: Bos
authors.affiliation: Department of Pediatrics, Medical Center Leeuwarden, Henri Dunantweg 2, 8934 AD, Leeuwarden, the Netherlands.
authors.forename: Tjalling W
authors.initials: TW
authors.lastname: de Vries
authors.affiliation: Department of Psychiatry, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, the Netherlands.
authors.forename: Pieter J
authors.initials: PJ
authors.lastname: Hoekstra
authors.affiliation: Groningen Research Institute of Pharmacy, PharmacoTherapy, -Epidemiology & -Economics, University of Groningen, Antionius Deuginslaan 1, 9713 AV, Groningen, the Netherlands.|Department of Epidemiology, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, the Netherlands.
authors.forename: Eelko
authors.initials: E
authors.lastname: Hak
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002648:Child; D004521:Educational Measurement / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D009426:Netherlands / Q000453:epidemiology; D012189:Retrospective Studies; D012574:Schools
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate
keywords: Attention-deficit/hyperactivity disorder; Methylphenidate; Pediatrics; School performance