Understanding Attention Deficit/Hyperactivity Disorder (ADHD) Part 2

In part two of my latest series on attention deficit/hyperactivity disorder (ADHD) we take a closer look at the nature of the disorder.

These positron emission tomography (PET) scans show that patients with ADHD had lower levels of dopamine transporters in the nucleus accumbens, a part of the brain’s reward center, than control subjects.

What is attention deficit/hyperactivity disorder?

Do you remember a classmate who just could not sit still or another who just sat quietly in the corner, day dreaming and looking out the window but when called on by the teacher did not know what was going on? Today both of these children might be diagnosed with ADHD. Indeed some still argue that there is no such thing as ADHD – that it is an artificially conceived diagnosis to aid the selling of prescription drugs and that in previous times a child with ‘ADHD’ was no more than considered to be no more than ‘bored’,’ restless’ or ‘giddy’.

Prognosis

ADHD was first described more than 100 years ago and its symptoms include excessively inattentive, hyperactive, or impulsive behaviours. For instance, children with ADHD find it more difficult to focus and to complete their schoolwork. ADHD affects up to eight in one hundred children and in over half the cases, it continues to persist into adulthood.Although most individuals with ADHD do not outgrow the disorder, their symptoms often change as they grow older, with less hyperactivity as adults. Problems with attention tend to continue into adulthood. There is no cure for ADHD at this time.

Possible causes

Recent brain imaging studies have shown a reduction in the levels of the neurotransmitters dopamine and noradrenaline in at least some people with the disorder. Because the nerve circuits in the prefrontal brain regions, which are normally involved in attention, require high levels of dopamine and noradrenaline stimulation, reduced levels of these two neurotransmitters could potentially lead to the weakened regulation of attention and behavior observed in ADHD .Altered brain activity also has been observed in particular nerve circuits connecting the cortex (outer part), striatum (deeper parts), and cerebellum (back of the neck), particularly in the right brain hemisphere with a delay in cortical development seen in some children with ADHD.
In part three of this series,  I will explain more what neuroscientists mean by ‘attention’, where it is found in the brain and how it is affected in ADHD.

Other Sources:
http://www.webmd.com/add-adhd/guide/

Part 1: Understanding ADHD and Learning Disability

 

Weekly Neuroscience Update

New research from Weizmann Institute, published in Nature Neuroscience has discovered that people can actually learn during sleep, which can unconsciously modify their behavior while awake.

Studies have shown that listening to music can soothe hospital patients, improve stroke outcomes and promote the releaseof the neurotransmitter dopamine in the brain sending pleasure signals throughout the body. Now findings recently presented at the Association for the Scientific Study of Consciousness suggest that playing familiar music could enhance cognitive response among patients with brain damage.

In a major development  Bionic Vision Australia researchers have successfully performed the first implantation of an early prototype bionic eye with 24 electrodes.

Researchers have discovered two gene variants that raise the risk of the pediatric cancer neuroblastoma. Using automated technology to perform genome-wide association studies on DNA from thousands of subjects, the study broadens understanding of how gene changes may make a child susceptible to this early childhood cancer, as well as causing a tumor to progress.

In a study published in the Journal of Neurology, researchers claim that because Attention Deficit Hyperactivity Disorder (ADHD), Fetal Alcohol Spectrum Disorder (FASD) and Parkinson’s Disease (PD) each involve ocular control and attention dysfunctions, they can be easily identified through an evaluation of how patients move their eyes while they watch television.

A new study by researchers at NYU School of Medicine reveals for the first time that metabolic syndrome (MetS) is associated with cognitive and brain impairments in adolescents and calls for pediatricians to take this into account when considering the early treatment of childhood obesity.

People whose blood sugar is on the high end of the normal range may be at greater risk of brain shrinkage that occurs with aging and diseases such as dementia, according to new research published in the September 4, 2012, print issue of Neurology®, the medical journal of the American Academy of Neurology.

Weekly Neuroscience Update

A growing body of evidence suggests that learning to play an instrument and continuing to practice and play it may offer mental benefits throughout life. Hearing has also been shown to be positively affected by making music. The latest study, published in the July issue of Frontiers in Human Neuroscience, shows that musical instrument training may reduce the effects of mental decline associated with aging. The research found that older adults who learned music in childhood and continued to play an instrument for at least 10 years outperformed others in tests of memory and cognitive ability.

Neuroscientists are finding that, as we get older, our aging brains are proving surprisingly malleable, and in ways not previously anticipated. But there are limitations. There is growing evidence that, beyond what was previously believed, the adult human brain is remarkably malleable and capable of new feats — even in the last decades of life. And UCLA researchers found that older adults who regularly used a brain fitness program played on a computer demonstrated significantly improved memory and language skills.

From older to younger brains now…

Determining when a teenage brain becomes an adult brain is not an exact science but it’s getting closer, according to an expert in adolescent developmental psychology, speaking at the American Psychological Association’s 120th Annual Convention.

Researchers at Aalto University in Finland have developed the world’s first device designed for mapping the human brain that combines whole-head magnetoencephalography (MEG) and magnetic resonance imaging (MRI) technology. MEG measures the electrical function and MRI visualizes the structure of the brain. The merging of these two technologies will produce unprecedented accuracy in locating brain electrical activity non-invasively

According to a study conducted by the National Institutes of Health, children with attention-deficit/hyperactivity disorder (ADHD) experience a developmental delay in frontal regions of the brain.

The brain differences found in people with schizophrenia are mainly the result of the disease itself or its treatment, as opposed to being caused by genetic factors, according to a Dutch study

Bilingual children outperform children who speak only one language in problem-solving skills and creative thinking, according to research led at the University of Strathclyde.

When we focus intently on one task, we often fail to see other things in plain sight – a phenomenon known as ‘inattention blindness’. Scientists already know that performing a task involving high information load – a ‘high load’ task – reduces our visual cortex response to incoming stimuli. Now researchers from UCL have examined the brain mechanisms behind this, further explaining why our brain becomes ‘blind’ under high load.

Weekly Neuroscience Update

UC Santa Barbara scientists turned to the simple sponge to find clues about the evolution of the complex nervous system and found that, but for a mechanism that coordinates the expression of genes that lead to the formation of neural synapses, sponges and the rest of the animal world may not be so distant after all.

Scientists have discovered a mechanism which stops the process of forgetting anxiety after a stress event. In experiments they showed that feelings of anxiety don’t subside if too little dynorphin is released into the brain. The results can help open up new paths in the treatment of trauma patients. The study has been published in the current edition of the Journal of Neuroscience.

The biological role of a gene variant implicated in multiple sclerosis (MS) has been determined by researchers at Oxford University. The finding explains why MS patients do badly on a set of drugs used successfully in other autoimmune diseases, such as rheumatoid arthritis and inflammatory bowel disease – something that has been a puzzle for over 10 years.

A clinical trial of an Alzheimer’s disease treatment developed at MIT has found that the nutrient cocktail can improve memory in patients with early Alzheimer’s. The results confirm and expand the findings of an earlier trial of the nutritional supplement, which is designed to promote new connections between brain cells.

An international consortium, has taken cells from Huntington’s Disease patients and generated human brain cells that develop aspects of the disease in the laboratory. The cells and the new technology will speed up research into understanding the disease and also accelerate drug discovery programs aimed at treating this terminal, genetic disorder. 

Stem cells that come from a specific part of the developing brain help fuel the growth of brain tumors caused by an inherited condition, researchers at Washington University School of Medicine in St. Louis report.

Findings from the first study directly examining gamma-aminobutyric acid (GABA) concentrations in the brains of children with ADHD were published last week in the Archives of General Psychiatry. In this new article researchers report finding significantly lower concentrations of GABA in the cerebral cortexes of children diagnosed with ADHD, compared with typically developing children. GABA is the brain’s main inhibitory neurotransmitter. The differences were detected in the region of the brain that controls voluntary movement.

People who are born deaf process the sense of touch differently than people who are born with normal hearing, according to research funded by the National Institutes of Health. The finding reveals how the early loss of a sense— in this case hearing—affects brain development. It adds to a growing list of discoveries that confirm the impact of experiences and outside influences in molding the developing brain. The study is published in the July 11 online issue of The Journal of Neuroscience.

Neuronal abnormalities in the brains of children with obstructive sleep apnea are reversible with treatment, a prospective study has shown.

Although many areas of the human brain are devoted to social tasks like detecting another person nearby, a new study has found that one small region carries information only for decisions during social interactions. Specifically, the area is active when we encounter a worthy opponent and decide whether to deceive them. A brain imaging study conducted by researchers at the Duke Center for Interdisciplinary Decision Science (D-CIDES) put human subjects through a functional MRI brain scan while playing a simplified game of poker against a computer and human opponents. Using computer algorithms to sort out what amount of information each area of the brain was processing, the team found only one brain region — the temporal-parietal junction, or TPJ — carried information that was unique to decisions against the human opponent.

 

Neuroscience News

Is Angry Birds keeping your brain healthy?

A new study from the Archives of Neurology says playing brain stimulating games can improve your memory and delay or prevent the onset of Alzheimer’s disease.

A new study suggests hearing metaphors can activate brain regions involved in sensory experience.

Whether you are an athlete, a musician or a stroke patient learning to walk again, practice can make perfect, but more practice may make you more efficient, according to a surprising new University of Colorado Boulder study.

Researchers have found a way to study how our brains assess the behavior – and likely future actions – of others during competitive social interactions. Their study, described in a paper in the Proceedings of the National Academy of Sciences, is the first to use a computational approach to tease out differing patterns of brain activity during these interactions, the researchers report.

A molecular path from our body’s internal clock to cells controlling rest and activity have been revealed.

A new study looks at how our brain processes visual information to prevent collisions.

Can Brain Scans of Young Children Predict Reading Problems?  Brain scientists are studying whether they can predict which young children may struggle with reading, in order to provide early help.

Virtual therapists being developed to treat depression. Scientists at a U.S. university are developing new technologies to treat depression and other disorders — including a mood-detecting smart phone that will call to check up on you.

A new study shows how to boost the power of pain relief without drugs.

Neuroscience could change the face of warfare. Soldiers could have their minds plugged directly into weapons systems, undergo brain scans during recruitment and take courses of neural stimulation to boost their learning, if the armed forces embrace the latest developments in neuroscience to hone the performance of their troops

Brain activity differs when one plays against others. Researchers have found a way to study how our brains assess the behavior – and likely future actions – of others during competitive social interactions. Their study, described in a paper in the Proceedings of the National Academy of Sciences, is the first to use a computational approach to tease out differing patterns of brain activity during these interactions, the researchers report.

Reporting in PLoS Biology, researchers write that they were able to correlate words a person was hearing to specific electrical activity in the brain. Neuroscientist Robert Knight, a co-author of the study, discusses future applications of this research and concerns that it amounts to mental wiretapping.

Brains may be wired for addiction.  Abnormalities in the brain may make some people more likely to become drug addicts, according to scientists at the University of Cambridge.

Patients’ Brains May Adapt to ADHD Medication. New research reveals how the brain appears to adapt to compensate for the effects of long-term ADHD medication, suggesting why ADHD medication is more effective short-term than it is long-term.

A two-year study of high school football players suggests that concussions are likely caused by many hits over time and not from a single blow to the head, as commonly believed.

Weekly Round Up

Finnish researchers have developed a groundbreaking new method that allows them to study how the brain processes different aspects of music, such as rhythm, tonality and timbre (sound color) in a realistic listening situation. The study is pioneering in that it for the first time reveals how wide networks in the brain, including areas responsible for motor actions, emotions, and creativity, are activated during music listening. The new method helps us understand better the complex dynamics of brain networks and the way music affects us.

Dreaming may act like a type of overnight therapy, taking the edge off painful memories, a new study says.

Connectivity is a hot topic in neuroscience these days. Instead of trying to figure out what individual brain regions do, researchers are focusing more on how regions work together as a network to enable memory, language, and decision-making. Now, a study of more than 100 children finds that interconnected brain regions develop in concert through childhood and adolescence. The researchers say their work could have implications for understanding various puzzles in neuroscience, such as what goes wrong in autism or why adolescent boys are prone to risky behavior.

Using functional magnetic resonance imaging (fMRI), researchers have identified abnormalities in the brains of children with attention deficit/hyperactivity disorder (ADHD) that may serve as a biomarker for the disorder.

People who meditate seem to be able ‘switch off’ areas of the brain associated with daydreaming as well as psychiatric disorders such as autism and schizophrenia, according to a new brain imaging study published in the Proceedings of the National Academy of Sciences.

Sustained changes in the region of the brain associated with cognitive function and emotional control were found in young adult men after one week of playing violent video games, according to study results presented by Indiana University School of Medicine researchers at the annual meeting of the Radiological Society of North America.