title: Predictors of treatment outcome in adults with ADHD treated with OROS® methylphenidate.
abstract: BACKGROUND
  We conducted a post-hoc analysis of the Long-Acting MethylpheniDate in Adult attention-deficit hyperactivity disorder (LAMDA) study to investigate predictors of response in adults with ADHD randomly assigned to Osmotic Release Oral System (OROS)(®)-methylphenidate hydrochloride (MPH) 18, 36 or 72 mg or placebo.
  
  
  METHODS
  LAMDA comprised a 5-week, double-blind (DB) period, followed by a 7-week, open-label (OL) period. A post-hoc analysis of covariance and a logistic regression analysis were undertaken to detect whether specific baseline parameters or overall treatment compliance during the double-blind phase contributed to response. The initial model included all covariates as independent variables; a backward stepwise selection method was used, with stay criteria of p<0.10. Six outcomes were considered: change from baseline CAARS:O-SV (physician-rated) and CAARS:S-S (self-report) scores at DB and OL end points, and response rate (≥30% decrease in CAARS:O-SV score from baseline) and normalization of CAARS:O-SV score at DB end point.
  
  
  RESULTS
  Taking into account a significant effect of OROS(®)-MPH treatment versus placebo in the original analysis (p≤0.015), across the outcomes considered in this post-hoc analysis, higher baseline CAARS scores were most strongly predictive of superior outcomes. Male gender and lower academic achievement were also predictive for improved results with certain outcomes.
  
  
  CONCLUSIONS
  Several baseline factors may help to predict better treatment outcomes in adults receiving OROS(®)-MPH; however, further research is required to confirm these findings and examine their neurobiological underpinnings.
authors.affiliation: UMC St. Radboud, Department of Cognitive Neuroscience, Nijmegen, The Netherlands. j.buitelaar@psy.umcn.nl
authors.forename: Jan K
authors.initials: JK
authors.lastname: Buitelaar
authors.forename: J J Sandra
authors.initials: JJ
authors.lastname: Kooij
authors.forename: J Antoni
authors.initials: JA
authors.lastname: Ramos-Quiroga
authors.forename: Joachim
authors.initials: J
authors.lastname: Dejonckheere
authors.forename: Miguel
authors.initials: M
authors.lastname: Casas
authors.forename: Joop C
authors.initials: JC
authors.lastname: van Oene
authors.forename: Barbara
authors.initials: B
authors.lastname: Schäuble
authors.forename: Goetz-Erik
authors.initials: GE
authors.lastname: Trott
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D008875:Middle Aged; D009995:Osmosis; D010919:Placebos; D011569:Psychiatric Status Rating Scales; D012727:Sex Characteristics; D016896:Treatment Outcome
chemical_list: D000697:Central Nervous System Stimulants; D003692:Delayed-Action Preparations; D010919:Placebos; D008774:Methylphenidate