title: Specificity of basic information processing and inhibitory control in attention deficit hyperactivity disorder.
abstract: BACKGROUND
  Both inhibitory-based executive functioning (IB-EF) and basic information processing (BIP) deficits are found in clinic-referred attention deficit hyperactivity disorder (ADHD) samples. However, it remains to be determined whether: (1) such deficits occur in non-referred samples of ADHD; (2) they are specific to ADHD; (3) the co-morbidity between ADHD and oppositional defiant disorder/conduct disorder (ODD/CD) has additive or interactive effects; and (4) IB-EF deficits are primary in ADHD or are due to BIP deficits.
  
  
  METHODS
  We assessed 704 subjects (age 6-12 years) from a non-referred sample using the Development and Well-Being Assessment (DAWBA) and classified them into five groups: typical developing controls (TDC; n = 378), Fear disorders (n = 90), Distress disorders (n = 57), ADHD (n = 100), ODD/CD (n = 40) and ADHD+ODD/CD (n = 39). We evaluated neurocognitive performance with a Two-Choice Reaction Time Task (2C-RT), a Conflict Control Task (CCT) and a Go/No-Go (GNG) task. We used a diffusion model (DM) to decompose BIP into processing efficiency, speed-accuracy trade-off and encoding/motor function along with variability parameters.
  
  
  RESULTS
  Poorer processing efficiency was found to be specific to ADHD. Faster encoding/motor function differentiated ADHD from TDC and from fear/distress whereas a more cautious (not impulsive) response style differentiated ADHD from both TDC and ODD/CD. The co-morbidity between ADHD and ODD/CD reflected only additive effects. All ADHD-related IB-EF classical effects were fully moderated by deficits in BIP.
  
  
  CONCLUSIONS
  Our findings challenge the IB-EF hypothesis for ADHD and underscore the importance of processing efficiency as the key specific mechanism for ADHD pathophysiology.
authors.affiliation: National Institute of Developmental Psychiatry for Children and Adolescents - CNPq, São Paulo, Brazil.
authors.forename: G A
authors.initials: GA
authors.lastname: Salum
authors.affiliation: Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Sergeant
authors.affiliation: University of Southampton, UK.
authors.forename: E
authors.initials: E
authors.lastname: Sonuga-Barke
authors.affiliation: University of California, USA.
authors.forename: J
authors.initials: J
authors.lastname: Vandekerckhove
authors.affiliation: National Institute of Developmental Psychiatry for Children and Adolescents - CNPq, São Paulo, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Gadelha
authors.affiliation: National Institute of Developmental Psychiatry for Children and Adolescents - CNPq, São Paulo, Brazil.
authors.forename: P M
authors.initials: PM
authors.lastname: Pan
authors.affiliation: National Institute of Developmental Psychiatry for Children and Adolescents - CNPq, São Paulo, Brazil.
authors.forename: T S
authors.initials: TS
authors.lastname: Moriyama
authors.affiliation: National Institute of Developmental Psychiatry for Children and Adolescents - CNPq, São Paulo, Brazil.
authors.forename: A S
authors.initials: AS
authors.lastname: Graeff-Martins
authors.affiliation: National Institute of Developmental Psychiatry for Children and Adolescents - CNPq, São Paulo, Brazil.
authors.forename: P Gomes
authors.initials: PG
authors.lastname: de Alvarenga
authors.affiliation: National Institute of Developmental Psychiatry for Children and Adolescents - CNPq, São Paulo, Brazil.
authors.forename: M C
authors.initials: MC
authors.lastname: do Rosário
authors.affiliation: National Institute of Developmental Psychiatry for Children and Adolescents - CNPq, São Paulo, Brazil.
authors.forename: G G
authors.initials: GG
authors.lastname: Manfro
authors.affiliation: National Institute of Developmental Psychiatry for Children and Adolescents - CNPq, São Paulo, Brazil.
authors.forename: G
authors.initials: G
authors.lastname: Polanczyk
authors.affiliation: National Institute of Developmental Psychiatry for Children and Adolescents - CNPq, São Paulo, Brazil.
authors.forename: L A P
authors.initials: LA
authors.lastname: Rohde
mesh_terms: D000704:Analysis of Variance; D019958:Attention Deficit and Disruptive Behavior Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology*; D016022:Case-Control Studies; D002648:Child; D015897:Comorbidity; D003937:Diagnosis, Differential; D056344:Executive Function / Q000502:physiology*; D005239:Fear / Q000523:psychology; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D007406:Interview, Psychological; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D015233:Models, Statistical; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011930:Reaction Time / Q000502:physiology; D013315:Stress, Psychological / Q000523:psychology