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Attention Deficit/Hyperactivity Disorder (ADHD) has been associated with atypical patterns of neural activity measured by electroencephalography (EEG). However, the identification of EEG diagnostic biomarkers has been complicated by the disorder's heterogeneity. The objective of this review was to synthesize the literature investigating EEG variation in patients diagnosed with ADHD, addressing the following questions: 1) Are the diagnostic ADHD subtypes associated with different EEG characteristics? 2) Are EEG measures correlated with ADHD traits and/or symptom severity? and 3) Do classification techniques using EEG measures reveal different clinical presentations of ADHD? Outcomes highlight the potential for electrophysiological measures to provide meaningful insights into the heterogeneity of ADHD, although direct translation of EEG biomarkers for diagnostic purposes is not yet supported. Key measures that show promise for the discrimination of existing ADHD subtypes and symptomatology include: resting state and task-related modulation of alpha, beta and theta power, and the event-related N2 and P3 components. Prescriptions are discussed for future studies that may help to bridge the gap between research and clinical application. • Electrophysiology provides meaningful insight into the heterogeneity of ADHD. • Attentional, inhibitory control, and resting tasks are compared in ADHD subtypes. • Power spectrum and event-related potential analyses are related to ADHD symptoms. • EEG shows promise for the discovery of novel subgroups of ADHD. [ABSTRACT FROM AUTHOR]

Background: Attention-deficit/hyperactivity disorder (ADHD) is a heterogeneous behavioral disorder, complex both in etiology and clinical expression. Both genetic and environmental factors have been implicated, and it has been suggested that gene-environment interactions may play a pivotal role in the disorder. Recently, a significant association was reported between ADHD and LPHN3 (which codes for latrophilin 3), and replicated in independent samples. Methods: We have examined the association between tag single nucleotide polymorphisms (SNPs) in LPHN3 within the region previously implicated in ADHD. Family based association tests (FBAT) were conducted ( n = 380 families) with the categorical diagnosis of ADHD, behavioral and cognitive phenotypes related to ADHD, and response to treatment (given a fixed dose of methylphenidate, 0.5 mg/day). Stratified FBAT analyses, based on maternal smoking and stress during pregnancy, was conducted. Results: Whereas limited association was observed in the total sample, highly significant interaction between four LPHN3 tag SNPs (rs6551665, rs1947274, rs6858066, rs2345039) and maternal stress during pregnancy was noted. Analysis conducted in the sub-group of mothers exposed to minimal stress during pregnancy showed significant associations with ADHD, behavioral and cognitive dimensions related to ADHD, as well as treatment response. Although extensive association was observed with the candidate SNPs, the findings are partially inconsistent with previously published results with the opposite alleles over-transmitted in these studies. Conclusions: These results provide evidence for the interaction between a genetic and environmental factor independently shown to be associated with ADHD. If confirmed in independent large studies, they may present a step forward in unraveling the complex etiology of ADHD. [ABSTRACT FROM AUTHOR]

The article focuses on the case of an 8-year old child named G.R. who manifests difficulties of attention and learning. It cites that the conducted investigations on the deficiency show that his achievements in the Continuous Performance Task are in clinical range. Further, the cited case of G.R. indicates diagnostic attention deficit disorder due to clear evidences of symptoms.

Objective: To assess the sensitivity of scales (Conners' Global Index Parent and Teacher form [CGI-P, CGI-T], Clinical Global Impression Scale [CGI], Continuous Performance Test [CPT], and Restricted Academic Situation Scale [RASS]) in evaluating improvement in symptomatology with methylphenidate in different Attention Deficit Hyperactivity Disorder (ADHD) subtypes. Method: Four hundred and ninety children (309 with ADHD Combined/Hyperactive [ADHD-CH] and 181 with ADHD Inattentive subtype [ADHD-I]) participated in a two week double-blind placebo-controlled crossover methylphenidate trial. Results: CGI-P showed small effect size for ADHD-I and medium effect size for the ADHD-CH subtype. CGI-T showed medium effect size for ADHD-I and large effect size for ADHD-CH subtype. CGI and RASS showed large effect size while CPT showed medium effect size for both subtypes. Conclusion: Acute behavioural assessments by clinicians (CGI, RASS) are better at detecting improvement with medication in all subtypes than parent or teacher reports (CGI-P, CGI-T). CGI-T is better than CGI-P for ADHD-I in detecting change in symptomatology as there is a greater demand for attention at school. [ABSTRACT FROM AUTHOR]

Objective: Maternal stress during pregnancy (MSDP) has been linked to a decrease in Intelligence Quotient (IQ) in the general population. The purpose of this study is to first examine the association between MSDP and IQ in children with Attention-Deficit/Hyperactivity Disorder (ADHD) and second, to confirm, in a large sample, the link between MSDP and ADHD behavioral symptomatology. Methods: Four hundred ten children diagnosed with ADHD, ages six to 12, were consecutively recruited from the ADHD clinic and day hospital at the Douglas Institute from 1999 to 2013. IQ was assessed using the WISC III and IV. Symptom severity was evaluated using the Child Behavior Checklist (CBCL) and Connor's Global Index for Parents (CGI-P) and Teachers (CGI-T). Results: No significant effect of MSDP on full scale IQ was observed, but MSDP had a significant effect on CBCL and CGI scores. Elevated MSDP was significantly associated with increased CBCL internalizing scores (β=4.2, p<.01), CBCL externalizing scores (β=1.9, p=.04), CGI-P restless-impulsive scores (β=2.6, p=.01), CGI-P emotional lability scores (β=3.1, p=.02), and CGI-T restless-impulsive (β=2.2, p=.05) and emotional lability (β=3.4, p=.04) scores. MSDP increased the variance explained of ADHD symptomatology even after controlling for various factors (i.e. familial income, parental education, smoking and drinking during pregnancy, gender and age). Conclusion: The study demonstrates that in children with ADHD, MSDP does not have an impact on IQ but rather on ADHD symptomatology, highlighting the importance of potentially offering psychological and social support to mothers who experience stress during pregnancy. [ABSTRACT FROM AUTHOR]