Directions of Aetiologic Research on Attention Deficit Hyperactivity Disorder

1998 ◽  
Vol 32 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Florence Levy ◽  
Cathy Ban ◽  
Glen Sunohara
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Brain Imaging ◽  
Attention Deficit ◽  
Future Research ◽  
Genetic Studies ◽  
Hyperactivity Disorder ◽  
Dopaminergic Systems ◽  
Targeted Treatments ◽  
The Central Nervous System ◽  
Magnetic Resonance Imaging Mri

Objective: The aim of this paper is to review and integrate recent literature on aetiological factors that have been postulated for attention deficit hyperactivity disorder (ADHD). Method: Recent studies relating to perinatal brain damage, intra-uterine toxic effects, neurochemical, brain imaging and genetic studies are reviewed, and those considered most significant are discussed. Where possible, recent findings are integrated and directions of future research are suggested. Clinical implications are briefly discussed. Results: Perinatal studies indicate that children with a birth weight under 750 g may be disadvantaged for attentional skills. Magnetic resonance imaging (MRI) and steady state visually evoked potential studies show differences in prefrontal, caudate and parietal areas in ADHD children, suggesting right hemispheric dysfunction. Functional MRI studies hold promise in further elucidating attentional systems in the central nervous system that are involved in ADHD. Genetic studies suggest genes related to dopaminergic systems may be important. Conclusions: Recent research on ADHD has made considerable advances, particularly in the areas of brain imaging and genetic studies. Genetic studies should provide further aetiological understandings of ADHD, leading to more targeted treatments.

scholarly journals Genetic variations influence brain changes in patients with attention-deficit hyperactivity disorder

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Santosh K. Yadav ◽  
Ajaz A. Bhat ◽  
Sheema Hashem ◽  
Sabah Nisar ◽  
Madeeha Kamal ◽  
...  
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Brain Imaging ◽  
Attention Deficit ◽  
Genetic Variations ◽  
Imaging Genetics ◽  
Treatment Modalities ◽  
Genetic Studies ◽  
Hyperactivity Disorder ◽  
Clinical Biomarkers ◽  
The Impact

AbstractAttention-deficit hyperactivity disorder (ADHD) is a neurological and neurodevelopmental childhood-onset disorder characterized by a persistent pattern of inattentiveness, impulsiveness, restlessness, and hyperactivity. These symptoms may continue in 55–66% of cases from childhood into adulthood. Even though the precise etiology of ADHD is not fully understood, it is considered as a multifactorial and heterogeneous disorder with several contributing factors such as heritability, auxiliary to neurodevelopmental issues, severe brain injuries, neuroinflammation, consanguineous marriages, premature birth, and exposure to environmental toxins. Neuroimaging and neurodevelopmental assessments may help to explore the possible role of genetic variations on ADHD neuropsychobiology. Multiple genetic studies have observed a strong genetic association with various aspects of neuropsychobiological functions, including neural abnormalities and delayed neurodevelopment in ADHD. The advancement in neuroimaging and molecular genomics offers the opportunity to analyze the impact of genetic variations alongside its dysregulated pathways on structural and functional derived brain imaging phenotypes in various neurological and psychiatric disorders, including ADHD. Recently, neuroimaging genomic studies observed a significant association of brain imaging phenotypes with genetic susceptibility in ADHD. Integrating the neuroimaging-derived phenotypes with genomics deciphers various neurobiological pathways that can be leveraged for the development of novel clinical biomarkers, new treatment modalities as well as therapeutic interventions for ADHD patients. In this review, we discuss the neurobiology of ADHD with particular emphasis on structural and functional changes in the ADHD brain and their interactions with complex genomic variations utilizing imaging genetics methodologies. We also highlight the genetic variants supposedly allied with the development of ADHD and how these, in turn, may affect the brain circuit function and related behaviors. In addition to reviewing imaging genetic studies, we also examine the need for complementary approaches at various levels of biological complexity and emphasize the importance of combining and integrating results to explore biological pathways involved in ADHD disorder. These approaches include animal models, computational biology, bioinformatics analyses, and multimodal imaging genetics studies.

Attention Deficit Hyperactivity Disorder

2018 ◽  
Author(s):  
Steven W. Evans ◽  
Julie S. Owens ◽  
W. John Monopoli ◽  
Kari Benson
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Children And Adolescents ◽  
Attention Deficit ◽  
Randomized Clinical Trials ◽  
Evidence Base ◽  
Future Research ◽  
Hyperactivity Disorder ◽  
New Findings ◽  
Assessment And Treatment ◽  
Effective Assessment

Youth with attention deficit hyperactivity disorder experience impairment across multiple domains of functioning, with the characteristics changing with age. Thus, assessment and treatment must be appropriate for the home and school and relevant to the child’s developmental level. This chapter reviews effective assessment strategies for use with children and adolescents. Psychosocial treatments for children and adolescents are discussed separately, as the approaches with each group differ substantially. For children, strategies with a strong evidence base are described, and innovations and treatment modifications that have been examined recently are showcased. For adolescents, the results of the few randomized clinical trials conducted with this population are reviewed. A theoretical model for how to sequence treatments (i.e., intervention, medication, accommodations) for youth is referenced, and two case studies highlight this model, as well some of the new findings described in this chapter. Implications and recommendations for future research and practice are provided.

Current Treatments of Attention-Deficit/Hyperactivity Disorder

CNS Spectrums ◽  
2000 ◽  
Vol 5 (S3) ◽  
pp. s1-s8 ◽  
Author(s):  
Steven Pliszka ◽  
William W. Dodson ◽  
Thomas J. Spencer
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Attention Deficit ◽  
Genetic Disorder ◽  
Medication Administration ◽  
Childhood Onset ◽  
Genetic Studies ◽  
Hyperactivity Disorder ◽  
Functional Behavior ◽  
Stimulant Medications ◽  
The Brain

ABSTRACTAttention-deficit/hyperactivity disorder (ADHD) is a genetic disorder that affects both children and adults. Genetic studies have shown the heritability of ADHD to be higher than other psychiatric disorders. In addition, imaging studies have revealed various structural anomalies in the brain.Often ADHD persists into adulthood. The presentation of ADHD into adulthood most often results from childhood onset of ADHD. Symptoms of inattention and functional behavior tend to persist. These symptoms may often be less obvious, with less overt hyperactivity and impulsiveness.Stimulant medications remain the predominant choice for the treatment of ADHD. They are safe and offer good response. Common adverse reactions can usually be removed by changing the dose and the timing of medication administration. Of the second-line agents for treating ADHD, the tricyclic antidepressants have generated the most studies and have proved fairly efficacious.

The Validity of the DSM-IV Subtypes of Attention-Deficit/Hyperactivity Disorder

2005 ◽  
Vol 39 (5) ◽  
pp. 344-353 ◽  
Author(s):  
Bernardine S. C. Woo ◽  
Joseph M. Rey
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Attention Deficit ◽  
Age Distribution ◽  
The Other ◽  
Genetic Studies ◽  
Main Research ◽  
Hyperactivity Disorder ◽  
Dsm Iv ◽  
Almost All ◽  
All Treatment

Objective: To examine the validity of the three subtypes of ADHD defined by DSM-IV. Method: Studies published in English were identified through searches of literature databases. Results: Estimates of the prevalence of ADHD have increased as a result of the introduction of DSM-IV criteria. Factor analytical and genetic studies provide some support for the validity of the distinction between the three subtypes. However, diagnosis of the combined subtype seems more reliable than the other two subtypes, although reliability is largely unknown for the latter. The hyperactive-impulsive subtype, the least common, differs from the other two subtypes in age distribution, association with other factors and neuropsychological parameters. Almost all treatment trials are based on participants with the combined type. Conclusion: Data supporting the validity of the inattentive and hyperactive-impulsive subtypes of ADHD a decade after the publication of DSM-IV are still scarce. Given that inattention is the hypothesized core ADHD symptom, it remains to be demonstrated that hyperactive-impulsive children who are not inattentive have the same condition. One of the main research deficits refers to data on treatment of the inattentive and hyperactive impulsive subtypes.

scholarly journals Emotional Bias Modification in Youths with Attention Deficit Hyperactivity Disorder (ADHD): New Research Vista

2020 ◽  
Vol 17 (11) ◽  
pp. 4028
Author(s):  
Zhang Melvyn ◽  
Aloysius Chow ◽  
Ranganath Vallabhajosyula ◽  
Daniel SS Fung
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Cognitive Bias ◽  
Attention Deficit ◽  
Cognitive Biases ◽  
Preliminary Evidence ◽  
Cognitive Bias Modification ◽  
Emotional Dysregulation ◽  
Future Research ◽  
Hyperactivity Disorder ◽  
Bias Modification

Whilst cognitive bias modification was initially used in the treatment of anxiety disorders, it is also currently being used for the treatment of other psychopathologies. In fact, cognitive bias modification has been especially well-investigated amongst children and adolescents. A recent review suggests some evidence for the modification of interpretative biases amongst children with neurodevelopment disorders. There have since been other studies reporting of the existence of other cognitive biases, such as emotional biases, amongst individuals with attention deficit hyperactivity disorder (ADHD). This perspective article will discuss the epidemiology of ADHD and the nature of emotional biases that are present amongst individuals with ADHD. This perspective article also reviewed some of the studies that have assessed and modified emotional biases in individuals with ADHD. A total of three studies have been identified from the published literature that provide evidence for targeting emotional biases amongst individuals with ADHD. These studies provide us with preliminary evidence for the effectiveness of modifying emotional biases and how it could help in ameliorating symptoms related to emotional dysregulation. There needs to be future research in this area with further evidence supporting the effectiveness of modifying emotional biases. It is also crucial for future research to determine which of these tools is best at detecting such biases, and which of these tools are versatile enough and non-invasive that they could safely be implemented for both research and clinical needs.

scholarly journals Evidence of potential overdiagnosis and overtreatment of attention deficit hyperactivity disorder (ADHD) in children and adolescents: protocol for a scoping review

BMJ Open ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. e032327 ◽  
Author(s):  
Luise Kazda ◽  
Katy Bell ◽  
Rae Thomas ◽  
Kevin McGeechan ◽  
Alexandra Barratt
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Children And Adolescents ◽  
Scoping Review ◽  
Attention Deficit ◽  
Comprehensive Evaluation ◽  
Cochrane Library ◽  
Future Research ◽  
Hyperactivity Disorder ◽  
Published Evidence ◽  
Scoping Reviews

IntroductionWorldwide, attention deficit hyperactivity disorder (ADHD) diagnosis rates in children and adolescents have been increasing consistently over the past decades, fuelling a debate about the underlying reasons for this trend. While many hypothesise that a substantial number of these additional cases are overdiagnosed, to date there has been no comprehensive evaluation of evidence for or against this hypothesis. Thus, with this scoping review we aim to synthesise published evidence on the topic in order to investigate whether existing literature is consistent with the occurrence of overdiagnosis and/or overtreatment of ADHD in children and adolescents.Methods and analysisThe proposed scoping review will be conducted in the context of a framework of five questions, developed specifically to identify areas in medicine with the potential for overdiagnosis and overtreatment. The review will adhere to the Joanna Briggs Methodology for Scoping Reviews. We will search Medline, Embase, PsycINFO and the Cochrane Library electronic databases for primary studies published in English from 1979 onwards. We will also conduct forward and backward citation searches of included articles. Data from studies that meet our predefined exclusion and inclusion criteria will be charted into a standardised extraction template with results mapped to our predetermined five-question framework in the form of a table and summarised in narrative form.Ethics and disseminationThe proposed study is a scoping review of the existing literature and as such does not require ethics approval. We intend to disseminate the results from the scoping review through publication in a peer-reviewed journal and through conference presentations. Further, we will use the findings from our scoping review to inform future research to fill key evidence gaps identified by this review.

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