R J Schachar

Summary

Affiliation: The Hospital for Sick Children
Country: Canada

Publications

  1. pmc Response inhibition and ADHD traits: correlates and heritability in a community sample
    J Crosbie
    Neurosciences and Mental Health Program, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Canada
    J Abnorm Child Psychol 41:497-507. 2013
  2. ncbi request reprint Confirmation of an inhibitory control deficit in attention-deficit/hyperactivity disorder
    R Schachar
    Department of Psychiatry and the Brain and Behavior Program, The Hospital for Sick Children and the University of Toronto, Ontario, Canada
    J Abnorm Child Psychol 28:227-35. 2000
  3. ncbi request reprint Attention-deficit hyperactivity disorder: critical appraisal of extended treatment studies
    Russell Schachar
    Department of Psychiatry, University of Toronto, Division of Child and Adolescent Psychiatry, Brain and Behaviour Program, Research Institute, Hospital for Sick Children, Toronto, Ontaro
    Can J Psychiatry 47:337-48. 2002
  4. ncbi request reprint Reformulating attention-deficit/hyperactivity disorder according to signal detection theory
    V L Mota
    Department of Psychiatry, Hospital for Sick Children, Toronto, Canada
    J Am Acad Child Adolesc Psychiatry 39:1144-51. 2000
  5. ncbi request reprint Beyond words: how do children with ADHD and/or conduct problems process nonverbal information about affect?
    E B Cadesky
    Brain and Behavior Research Program, Hospital for Sick Children, Toronto, Canada
    J Am Acad Child Adolesc Psychiatry 39:1160-7. 2000
  6. ncbi request reprint Moderators and mediators of long-term adherence to stimulant treatment in children with ADHD
    D Thiruchelvam
    Department of Psychiatry, The Hospital for Sick Children and the University of Toronto, Ontario, Canada
    J Am Acad Child Adolesc Psychiatry 40:922-8. 2001
  7. ncbi request reprint Methylphenidate treatment of attention-deficit/hyperactivity disorder secondary to traumatic brain injury: a critical appraisal of treatment studies
    Charles Jin
    Department of Psychiatry, North Shore University Hospital, Manhasset, New York, USA
    CNS Spectr 9:217-26. 2004
  8. ncbi request reprint The serotonin receptor HTR1B: gene polymorphisms in attention deficit hyperactivity disorder
    Abel Ickowicz
    The Hospital for Sick Children, Toronto, Ontario, Canada
    Am J Med Genet B Neuropsychiatr Genet 144:121-5. 2007
  9. ncbi request reprint Parent-of-origin effects in attention-deficit hyperactivity disorder
    Lisa M Goos
    Department of Psychiatry, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
    Psychiatry Res 149:1-9. 2007
  10. ncbi request reprint Investigation of the G protein subunit Galphaolf gene (GNAL) in attention deficit/hyperactivity disorder
    Nancy Laurin
    Cell and Molecular Biology Division, Toronto Western Research Institute, University Health Network, Toronto, Ont, Canada
    J Psychiatr Res 42:117-24. 2008

Collaborators

Detail Information

Publications28

  1. pmc Response inhibition and ADHD traits: correlates and heritability in a community sample
    J Crosbie
    Neurosciences and Mental Health Program, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Canada
    J Abnorm Child Psychol 41:497-507. 2013
    ..ADHD traits and inhibition, but not latency or variability were coheritable. In the largest study in the general population, we found support for the validity of response inhibition as an endophenotype of ADHD...
  2. ncbi request reprint Confirmation of an inhibitory control deficit in attention-deficit/hyperactivity disorder
    R Schachar
    Department of Psychiatry and the Brain and Behavior Program, The Hospital for Sick Children and the University of Toronto, Ontario, Canada
    J Abnorm Child Psychol 28:227-35. 2000
    ..These results indicate that children with ADHD have deficient inhibition as measured in the stop-signal paradigm and that ADHD occurring in the presence of ADHD + CD may represent a phenocopy of CD rather than a variant of ADHD...
  3. ncbi request reprint Attention-deficit hyperactivity disorder: critical appraisal of extended treatment studies
    Russell Schachar
    Department of Psychiatry, University of Toronto, Division of Child and Adolescent Psychiatry, Brain and Behaviour Program, Research Institute, Hospital for Sick Children, Toronto, Ontaro
    Can J Psychiatry 47:337-48. 2002
    ..Only 1 study showed that combination therapy adds to the effects of medication. Rigorous treatment research among representative samples of ADHD individuals is needed...
  4. ncbi request reprint Reformulating attention-deficit/hyperactivity disorder according to signal detection theory
    V L Mota
    Department of Psychiatry, Hospital for Sick Children, Toronto, Canada
    J Am Acad Child Adolesc Psychiatry 39:1144-51. 2000
    ..The objective of this study was to enhance the diagnostic accuracy of ADHD by identifying the symptoms that are associated with impairment...
  5. ncbi request reprint Beyond words: how do children with ADHD and/or conduct problems process nonverbal information about affect?
    E B Cadesky
    Brain and Behavior Research Program, Hospital for Sick Children, Toronto, Canada
    J Am Acad Child Adolesc Psychiatry 39:1160-7. 2000
    ..To study nonverbal social cue perception in children with attention-deficit/hyperactivity disorder (ADHD; n = 86), conduct problems (CP; n = 24), or both disorders (ADHD + CP; n = 63), as well as normal controls (n = 27)...
  6. ncbi request reprint Moderators and mediators of long-term adherence to stimulant treatment in children with ADHD
    D Thiruchelvam
    Department of Psychiatry, The Hospital for Sick Children and the University of Toronto, Ontario, Canada
    J Am Acad Child Adolesc Psychiatry 40:922-8. 2001
    ..CONCLUSIONS: Adherence to stimulant medications is a significant factor in the long-term treatment of children with ADHD...
  7. ncbi request reprint Methylphenidate treatment of attention-deficit/hyperactivity disorder secondary to traumatic brain injury: a critical appraisal of treatment studies
    Charles Jin
    Department of Psychiatry, North Shore University Hospital, Manhasset, New York, USA
    CNS Spectr 9:217-26. 2004
    ..Are stimulants effective in treating attention-deficit/hyperactivity disorder secondary to traumatic brain injury (ADHD/TBI)? The authors reviewed and examined the current knowledge on efficacy of stimulant treatment ADHD/TBI...
  8. ncbi request reprint The serotonin receptor HTR1B: gene polymorphisms in attention deficit hyperactivity disorder
    Abel Ickowicz
    The Hospital for Sick Children, Toronto, Ontario, Canada
    Am J Med Genet B Neuropsychiatr Genet 144:121-5. 2007
    ..In addition we did not find evidence to suggest an association between HTR1B and perfectionism in this sample of ADHD families...
  9. ncbi request reprint Parent-of-origin effects in attention-deficit hyperactivity disorder
    Lisa M Goos
    Department of Psychiatry, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
    Psychiatry Res 149:1-9. 2007
    ..Interpretations of these data in terms of environmental and genetic factors, including epigenetic and sex-linked hypotheses, are explored...
  10. ncbi request reprint Investigation of the G protein subunit Galphaolf gene (GNAL) in attention deficit/hyperactivity disorder
    Nancy Laurin
    Cell and Molecular Biology Division, Toronto Western Research Institute, University Health Network, Toronto, Ont, Canada
    J Psychiatr Res 42:117-24. 2008
    ..005) and rs8098539A (P=0.035). These preliminary findings suggest a possible contribution of GNAL in the susceptibility to ADHD, with possible involvement of parent-of-origin effects...
  11. ncbi request reprint Restraint and cancellation: multiple inhibition deficits in attention deficit hyperactivity disorder
    Russell Schachar
    Psychiatry Research Unit, Department of Psychiatry, Brain and Behavior Programme, Research Institute, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, Ontario, Canada
    J Abnorm Child Psychol 35:229-38. 2007
    ..We conclude that ADHD is associated with deficits in both restraint and cancellation subcomponents of inhibition...
  12. ncbi request reprint The gene for synapsin III and attention-deficit hyperactivity disorder
    Rohit Makkar
    Cell and Molecular Biology Division, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
    Psychiatr Genet 17:109-12. 2007
    ..On the basis of the role of synapsin III in the modulation of neurotransmitter release, we tested this gene as a candidate contributing to the genetic susceptibility of attention deficit hyperactivity disorder...
  13. ncbi request reprint Symptoms of attention-deficit/hyperactivity disorder following traumatic brain injury in children
    Harvey Levin
    Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, TX 77030, USA
    J Dev Behav Pediatr 28:108-18. 2007
    ..The baseline assessment was performed within 1 month post-injury to establish preinjury diagnosis...
  14. ncbi request reprint Association study of the brain-derived neurotropic factor (BDNF) gene in attention deficit hyperactivity disorder
    Jonghun Lee
    Cell and Molecular Biology Division, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
    Am J Med Genet B Neuropsychiatr Genet 144:976-81. 2007
    ..651, P = 0.008). These results should be interpreted cautiously, however, because of the low haplotype frequency. In light of the evidence for an involvement of BDNF in ADHD, further analysis of the BDNF gene in ADHD is warranted...
  15. ncbi request reprint No evidence for genetic association between DARPP-32 (PP1R1B) polymorphisms and attention deficit hyperactivity disorder
    Nancy Laurin
    Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada
    Am J Med Genet B Neuropsychiatr Genet 147:339-42. 2008
    ..In conclusion, albeit a key regulatory role in dopamine signaling, our data do not support a major contribution of the DARPP-32 gene in ADHD...
  16. doi request reprint Cognitive and behavioral effects of multilayer-release methylphenidate in the treatment of children with attention-deficit/hyperactivity disorder
    Russell Schachar
    Hospital for Sick Children, Toronto, Ontario, Canada
    J Child Adolesc Psychopharmacol 18:11-24. 2008
    ....
  17. ncbi request reprint Gene for the serotonin transporter and ADHD: no association with two functional polymorphisms
    Karen G Wigg
    Department of Psychiatry, Cell and Molecular Division, The Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
    Am J Med Genet B Neuropsychiatr Genet 141:566-70. 2006
    ..These polymorphisms were genotyped in 209 ADHD families identified through an affected proband. We did not find evidence for an association of these polymorphisms, or haplotypes of these polymorphisms, to ADHD in this sample...
  18. ncbi request reprint Stimulant treatment over 5 years: effects on growth
    Alice Charach
    Department of Psychiatry, The Hospital for Sick Children, Toronto, Ontario, Canada
    J Am Acad Child Adolesc Psychiatry 45:415-21. 2006
    ..Long-term effects of psychostimulants on growth in height and in weight are investigated in children with attention-deficit/hyperactivity disorder...
  19. ncbi request reprint The norepinephrine transporter gene and attention-deficit hyperactivity disorder
    Cathy L Barr
    Department of Psychiatry and Division of Cellular and Molecular Biology, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
    Am J Med Genet 114:255-9. 2002
    ..8%) was similar to that previously reported in a control sample (2.2%), it is unlikely that this variant is related to the ADHD phenotype. Our results do not support the NET1 gene as a major genetic susceptibility factor in ADHD...
  20. ncbi request reprint Attention deficit hyperactivity disorder and the gene for dopamine Beta-hydroxylase
    Karen Wigg
    Department of Psychiatry, Toronto Western Hospital, Ont, Canada
    Am J Psychiatry 159:1046-8. 2002
    ..One recent study reported an association of an allele of the TaqI polymorphism located in the fifth intron of the gene for dopamine beta-hydroxylase (DBH). The authors' goal was to replicate this finding...
  21. ncbi request reprint Selective inhibition in children with attention-deficit hyperactivity disorder off and on stimulant medication
    Anne Claude Bedard
    Institute of Medical Science, The University of Toronto, Toronto, Canada
    J Abnorm Child Psychol 31:315-27. 2003
    ..On the one hand, findings are consistent with purported inhibition deficit in ADHD, but on the other hand, suggest that neither the impairment itself, nor MPH effects, were restricted to inhibition...
  22. ncbi request reprint Attention deficit hyperactivity disorder symptoms and response inhibition after closed head injury in children: do preinjury behavior and injury severity predict outcome?
    Russell Schachar
    Brain and Behavior, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
    Dev Neuropsychol 25:179-98. 2004
    ..Poor response inhibition is a consequence of CHI but only when the CHI is severe and the child manifests high levels of SADHD symptoms...
  23. ncbi request reprint Changes in working memory after traumatic brain injury in children
    Harvey S Levin
    Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, TX, USA
    Neuropsychology 18:240-7. 2004
    ..The Left Frontal Lesions x Age interaction approached significance. Mechanisms mediating late decline in WM and the effects of left frontal lesions are discussed...
  24. ncbi request reprint Stimulant treatment over five years: adherence, effectiveness, and adverse effects
    Alice Charach
    Department of Psychiatry, The Hospital for Sick Children and the University of Toronto, Research Institute, The Hospital for Sick Children, University of Toronto, Ontario, Canada
    J Am Acad Child Adolesc Psychiatry 43:559-67. 2004
    ..To evaluate the impact of adherence and medication status on effectiveness and adverse effects of stimulant use in children with attention-deficit/hyperactivity disorder (ADHD) over 5 years...
  25. ncbi request reprint Replication test for association of the IL-1 receptor antagonist gene, IL1RN, with attention-deficit/hyperactivity disorder
    Virginia L Misener
    Cell and Molecular Biology Division, Toronto Western Research Institute, University Health Network, Toronto, Ont, Canada
    Neuropsychobiology 50:231-4. 2004
    ..e. false-positive) result. These findings highlight the need for further investigations of this marker, in additional independent ADHD samples, in the future...
  26. ncbi request reprint Attention-deficit hyperactivity disorder with and without obsessive-compulsive behaviours: clinical characteristics, cognitive assessment, and risk factors
    Paul Daniel Arnold
    Neurogenetics Section, Child Psychiatry Program, Centre for Addiction and Mental Health, Toronto, Ontario
    Can J Psychiatry 50:59-66. 2005
    ....
  27. ncbi request reprint Correlates of methylphenidate use in Canadian children: a cross-sectional study
    Alice Charach
    Department of Psychiatry, Hospital for Sick Children, Toronto, Ontario
    Can J Psychiatry 51:17-26. 2006
    ..This study aimed to estimate the prevalence of methylphenidate (MPH) use among Canadian children aged 2 to 11 years, from 1994-1995 to 1998-1999 and to identify sociodemographic, child, and parent-family correlates are identified...
  28. ncbi request reprint Sequence variation in the 3'-untranslated region of the dopamine transporter gene and attention-deficit hyperactivity disorder (ADHD)
    Yu Feng
    Cell and Molecular Biology Division, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
    Am J Med Genet B Neuropsychiatr Genet 139:1-6. 2005
    ..Our results therefore refute the possibility of the reported DraI variation or alleles of the VNTR as the functional variants contributing to the disorder...