Philadelphia, PA, October 15, 2014 - Are deficits in attention limited to those with attention-deficit/hyperactivity disorder (ADHD) or is there a spectrum of attention function in the general population? The answer to this question has implications for psychiatric diagnoses and perhaps for society, broadly.
A new study published in the current issue of Biological Psychiatry, by researchers at Cardiff University School of Medicine and the University of Bristol, suggests that there is a spectrum of attention, hyperactivity/impulsiveness and language function in society, with varying degrees of these impairments associated with clusters of genes linked with the risk for ADHD.
Viewing these functions as dimensions or spectrums contrasts with a traditional view of ADHD as a disease category.
To answer this question, researchers led by senior author Dr. Anita Thapar used genetic data from patients with ADHD as well as data from the Avon Longitudinal Study of Parents and Children (ALSPAC). The ALSPAC is based in England and is a large, ongoing study of parents and children followed since birth in the early '90s.
They created polygenic risk scores - a 'composite' score of genetic effects that forms an index of genetic risk - of ADHD for 8,229 ALSPAC participants.
They found that polygenic risk for ADHD was positively associated with higher levels of traits of hyperactivity/impulsiveness and attention at ages 7 and 10 in the general population. It was also negatively associated with pragmatic language abilities, e.g., the ability to appropriately use language in social settings.
"Our research finds that a set of genetic risks identified from UK patients with a clinical diagnosis of childhood ADHD also predicted higher levels of developmental difficulties in children from a UK population cohort, the ALSPAC," said Thapar.
First author Joanna Martin added, "Our results provide support at a genetic level for the suggestion that ADHD diagnosis represents the extreme of a spectrum of difficulties. The results are also important as they suggest that the same sets of genetic risks contribute to different aspects of child development which are characteristic features of neurodevelopmental disorders such as ADHD and autism spectrum disorder."
"It may be the case that at some point polygenic risk scores may, in conjunction with other clinical information, help to identify children who will struggle in school and other demanding contexts due to attention difficulties," said Dr. John Krystal, Editor of Biological Psychiatry. "The objective of this type of early identification would be to provide children who are at risk for difficulties with support so that problems at school may be prevented."
The article is "Genetic Risk for Attention-Deficit/Hyperactivity Disorder Contributes to Neurodevelopmental Traits in the General Population" by Joanna Martin, Marian L. Hamshere, Evangelia Stergiakouli, Michael C. O'Donovan, Anita Thapar (doi: 10.1016/j.biopsych.2014.02.013). The article appears in Biological Psychiatry, Volume 76, Issue 8 (October 15, 2014), published by Elsevier.
Notes for editors
Full text of the article is available to credentialed journalists upon request; contact Rhiannon Bugno at +1 214 648 0880 or Biol.Psych@utsouthwestern.edu. Journalists wishing to interview the authors may contact Ms. Joanna Martin at MartinJM1@cardiff.ac.uk, or Dr. Anita Thapar at firstname.lastname@example.org or +44 029 20 688 478, ext. 88478.
The authors' affiliations, and disclosures of financial and conflicts of interests are available in the article.
John H. Krystal, M.D., is Chairman of the Department of Psychiatry at the Yale University School of Medicine, Chief of Psychiatry at Yale-New Haven Hospital, and a research psychiatrist at the VA Connecticut Healthcare System. His disclosures of financial and conflicts of interests are available here.
About Biological Psychiatry
Biological Psychiatry is the official journal of the Society of Biological Psychiatry, whose purpose is to promote excellence in scientific research and education in fields that investigate the nature, causes, mechanisms and treatments of disorders of thought, emotion, or behavior. In accord with this mission, this peer-reviewed, rapid-publication, international journal publishes both basic and clinical contributions from all disciplines and research areas relevant to the pathophysiology and treatment of major psychiatric disorders.
The journal publishes novel results of original research which represent an important new lead or significant impact on the field, particularly those addressing genetic and environmental risk factors, neural circuitry and neurochemistry, and important new therapeutic approaches. Reviews and commentaries that focus on topics of current research and interest are also encouraged.
Biological Psychiatry is one of the most selective and highly cited journals in the field of psychiatric neuroscience. It is ranked 5th out of 135 Psychiatry titles and 14th out of 251 Neurosciences titles in the Journal Citations Reports® published by Thomson Reuters. The 2013 Impact Factor score for Biological Psychiatry is 9.472.
Elsevier is a world-leading provider of information solutions that enhance the performance of science, health, and technology professionals, empowering them to make better decisions, deliver better care, and sometimes make groundbreaking discoveries that advance the boundaries of knowledge and human progress. Elsevier provides web-based, digital solutions -- among them ScienceDirect, Scopus, Elsevier Research Intelligence and ClinicalKey -- and publishes nearly 2,200 journals, including The Lancet and Cell, and over 25,000 book titles, including a number of iconic reference works.
The company is part of Reed Elsevier Group PLC, a world-leading provider of professional information solutions in the Science, Medical, Legal and Risk and Business sectors, which is jointly owned by Reed Elsevier PLC and Reed Elsevier NV. The ticker symbols are REN (Euronext Amsterdam), REL (London Stock Exchange), RUK and ENL (New York Stock Exchange).