Research Topics
| R J SchacharSummaryAffiliation: The Hospital for Sick Children Country: Canada Publications
| Collaborators
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Detail Information
Publications
Confirmation of an inhibitory control deficit in attention-deficit/hyperactivity disorderR 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...- Attention-deficit hyperactivity disorder: critical appraisal of extended treatment studiesRussell 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... - Reformulating attention-deficit/hyperactivity disorder according to signal detection theoryV 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... - 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)... - Moderators and mediators of long-term adherence to stimulant treatment in children with ADHDD 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... - Methylphenidate treatment of attention-deficit/hyperactivity disorder secondary to traumatic brain injury: a critical appraisal of treatment studiesCharles 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... - Gene for the serotonin transporter and ADHD: no association with two functional polymorphismsKaren 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... - The serotonin receptor HTR1B: gene polymorphisms in attention deficit hyperactivity disorderAbel 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... - Parent-of-origin effects in attention-deficit hyperactivity disorderLisa 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... - Investigation of the G protein subunit Galphaolf gene (GNAL) in attention deficit/hyperactivity disorderNancy 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... - Restraint and cancellation: multiple inhibition deficits in attention deficit hyperactivity disorderRussell 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... - The gene for synapsin III and attention-deficit hyperactivity disorderRohit 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... - Symptoms of attention-deficit/hyperactivity disorder following traumatic brain injury in childrenHarvey 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... - Association study of the brain-derived neurotropic factor (BDNF) gene in attention deficit hyperactivity disorderJonghun 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... - No evidence for genetic association between DARPP-32 (PP1R1B) polymorphisms and attention deficit hyperactivity disorderNancy 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... - Stimulant treatment over 5 years: effects on growthAlice 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... - Correlates of methylphenidate use in Canadian children: a cross-sectional studyAlice 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... - The norepinephrine transporter gene and attention-deficit hyperactivity disorderCathy 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... - Attention deficit hyperactivity disorder and the gene for dopamine Beta-hydroxylaseKaren Wigg
Department of Psychiatry, Toronto Western Hospital, Ont, Canada
Am J Psychiatry 159:1046-8. 2002..However, the authors observed some evidence for biased transmission of the same allele of the TaqI polymorphism, as previously reported. CONCLUSIONS: These findings suggest that the gene for DBH should be investigated further... - Selective inhibition in children with attention-deficit hyperactivity disorder off and on stimulant medicationAnne-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... - 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... - Changes in working memory after traumatic brain injury in childrenHarvey 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... - Stimulant treatment over five years: adherence, effectiveness, and adverse effectsAlice 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... - Replication test for association of the IL-1 receptor antagonist gene, IL1RN, with attention-deficit/hyperactivity disorderVirginia 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... - Attention-deficit hyperactivity disorder with and without obsessive-compulsive behaviours: clinical characteristics, cognitive assessment, and risk factorsPaul Daniel Arnold
Neurogenetics Section, Child Psychiatry Program, Centre for Addiction and Mental Health, Toronto, Ontario
Can J Psychiatry 50:59-66. 2005..Further, children with ADHD and OCB may develop symptoms as the result of different genetic and environmental risk factors, compared with children with ADHD only... - 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... 
Cognitive and behavioral effects of multilayer-release methylphenidate in the treatment of children with attention-deficit/hyperactivity disorderRussell Schachar
Hospital for Sick Children, Toronto, Ontario, Canada
J Child Adolesc Psychopharmacol 18:11-24. 2008....