Navigation Links
Alterations in the brain's reward system related to attention-deficit/hyperactivity disorder
Date:2/3/2010

Until now, attention-deficit/hyperactivity disorder (ADHD) was related to alterations in the brain affecting attention and cognitive processes. Researchers at Universitat Autnoma de Barcelona and the Vall d'Hebron University Hospital for the first time have discovered anomalies in the brain's reward system related to the neural circuits of motivation and gratification. In children with ADHD, the degree of motivation when carrying out an activity is related to the immediacy with which the objectives of the activity are met. This would explain why their attention and hyperactivity levels differ depending on the tasks being carried out.

Susanna Carmona, researcher at the Cognitive Neuroscience Unit of the UAB Department of Psychiatry and Legal Medicine (URNC-IAPS-Hospital del Mar), has worked in collaboration with clinical researchers of the Vall d'Hebron University Hospital on the first research which relates the structure of the brain's reward system, the ventral striatum, with clinical symptoms in children suffering from ADHD.

Models describing the origin of ADHD tend to emphasise the relevance of attention processes and of the cognitive functions which guide our mental processes in achieving proposed objectives. Nevertheless, recent research has focused on neural gratification/pleasure circuits, which can be found in what is known as the brain's reward system, with the nucleus accumbens as the central part of this system.

The nucleus accumbens is in charge of maintaining levels of motivation when commencing a task and continues to do so until reaching what experts name the "reinforcement", the proposed objective. This motivation can be maintained throughout time, even when the gratification obtained is not immediate. However, in children with ADHD motivational levels seem to drop rapidly and there is a need for immediate reinforcements to continue persisting in their efforts.

In this study, researchers selected a sample of 84 participants aged 6 to 18 years and divided them according to presence of ADHD symptoms, with one experimental group of 42 children with ADHD and one control group of 42 children with no signs of mental or behavioural anomalies, paired by sex and age. Magnetic resonance images were taken of all participants to view the structure of their brains. Of these images, the cerebral region corresponding to the ventral striatum, which includes the nucleus accumbens, was demarcated.

Differences in the structure of the ventral striatum - particularly on the right-hand side - could be seen between those with ADHD and those without the disorder. Children with ADHD exhibited reduced volumes in this region. These differences were associated with symptoms of hyperactivity and impulsiveness.

The obtained data corroborate results from previous studies carried out with animals: the importance of the reward system, as well as the relation between nucleus accumbens, impulsive behaviour and the development of motor hyperactivity. This leads researchers to consider that ADHD is not only caused by brain alterations affecting cognitive processes, but also by anomalies which cause motivational deficiencies. This would explain the imbalance in levels of attention and hyperactivity in a child with ADHD depending on his or her motivation when engaged in a specific task and the immediacy of the gratification/pleasure while carrying it out.


'/>"/>

Contact: Maria Jesus Delgado
MariaJesus.Delgado@uab.cat
34-935-814-049
Universitat Autonoma de Barcelona
Source:Eurekalert

Related medicine news :

1. Bacterial phylotype alterations in irritable bowel syndrome
2. Alterations in brains white matter key to schizophrenia, UCLA study shows
3. Gene alterations associated with response to anthracycline therapy for breast cancer
4. Older brains make good use of useless information
5. First Global, Virtual Summit on Cognitive Health and Performance Features 200 Sharp Brains
6. New Intra-Arrest Cooling Method May Save More Brains During Cardiac Arrest
7. Older Brains May Not Be So Small After All
8. Alzheimers Gene Affects Brains of Young Adults
9. Trauma From Iraq Could Alter Veterans Brains
10. As Waistlines Widen, Brains Shrink
11. Massachusetts General Hospital is Second in Nation to Acquire Both BrainSUITE(R) iMRI and iCT
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/28/2016)... ... ... a half of planning the Multiple Pathways of Recovery Conference , CCAR is pleased ... held May 2 -4, 2016 at the Mystic Marriott Hotel & Spa . ... pathways individuals use to get into and sustain their recovery. Pathways of recovery are ...
(Date:5/27/2016)... ... May 27, 2016 , ... More than a third of American adults are ... bariatric surgery has received increased attention in recent years, as an article ... to weight loss, most people are familiar with the basic requirements of maintaining a ...
(Date:5/27/2016)... Newark, NJ (PRWEB) , ... May 27, 2016 , ... ... been named as YWCA Tribute to Women and Industry (TWIN) 2016 honorees. The ... to their workplace. For this year, Geri Boone, Director of the MLTSS (Managed Long-Term ...
(Date:5/27/2016)... ... May 27, 2016 , ... An influential resource amongst nurses and ... to shed lights on the variety of topics detailing why we appreciate nurses in ... why this career has gone from being in a major recession to one of ...
(Date:5/27/2016)... ... May 27, 2016 , ... This campaign aims to provide a path to ... society can control and change. , As nearly 795,000 Americans suffering from a new ... United States. Plus, with an estimated 129,000 of these people dying from stroke, it’s ...
Breaking Medicine News(10 mins):
(Date:5/24/2016)...  Diana Russell suffers from a form of rheumatoid ... out.  This disease has put her in a wheelchair, ... grandchildren to leave her home.  Because of the size ... the wheelchair.  So if there is a family function, ... left to wait for the bus. Photo ...
(Date:5/24/2016)...  NxStage Medical, Inc. (Nasdaq: NXTM ), ... care, today announced that Jeffrey H. Burbank , ... schedule of investor conferences. Where applicable, a webcast of ... .   ... Friday, June 10, 2016 1:30 p.m. ET ...
(Date:5/24/2016)... Marziani has joined VMS BioMarketing as senior vice president of sales, announced Andrea ... Marziani will lead the company,s business development and sales team, exploring new opportunities for ... - http://photos.prnewswire.com/prnh/20160523/371089 ... ... ...
Breaking Medicine Technology: