Category: ADD and ADHD

A few minutes of exercise can help children with attention deficit hyperactivity disorder perform better academically, according to a new study led by a Michigan State University researcher.

The study, published in the current issue of the Journal of Pediatrics, shows for the first time that kids with ADHD can better drown out distractions and focus on a task after a single bout of exercise. Scientists say such "inhibitory control" is the main challenge faced by people with the disorder.

"This provides some very early evidence that exercise might be a tool in our nonpharmaceutical treatment of ADHD," said Matthew Pontifex, MSU assistant professor of kinesiology, who led the study. "Maybe our first course of action that we would recommend to developmental psychologists would be to increase children's physical activity."

While drugs have proven largely effective in treating many of the 2.5 million school-aged American children with ADHD, a growing number of parents and physicians worry about the side effects and costs of medication.

In the study, Pontifex and colleagues asked 40 children aged 8 to 10, half of whom had ADHD, to spend 20 minutes either walking briskly on a treadmill or reading while seated. The children then took a brief reading comprehension and math exam similar to longer standardized tests. They also played a simple computer game in which they had to ignore visual stimuli to quickly determine which direction a cartoon fish was swimming.

The results showed all of the children performed better on both tests after exercising. In the computer game, those with ADHD also were better able to slow down after making an error to avoid repeat mistakes — a particular challenge for those with the disorder.

Pontifex said the findings support calls for more physical activity during the school day. Other researchers have found that children with ADHD are less likely to be physically active or play organized sports. Meanwhile, many schools have cut recess and physical education programs in response to shrinking budgets.

"To date there really isn't a whole lot of evidence that schools can pull from to justify why these physical education programs should be in existence," he said. "So what we're trying to do is target our research to provide that type of evidence."

Pontifex conducted the study for his doctoral dissertation at the University of Illinois before joining the MSU faculty. His co-investigators included his adviser, kinesiology professor Charles Hillman, and Daniel Picchietti, a pediatrician at the Carle Foundation Hospital in Champaign, Ill. The research was funded by the National Institute of Child Health and Human Development.

Adults who suffer from attention-deficit and hyperactivity disorder (ADHD) are more than three times as likely to develop a common form of degenerative dementia than those without, according to research in the January issue of the European Journal of Neurology.

Researchers from Argentina confirmed the link during a study of 360 patients with degenerative dementia and 149 healthy controls, matched by age, sex and education. The dementia patients comprised 109 people with dementia with Lewy bodies (DLB) and 251 with Alzheimer's.

"Our study showed that 48 per cent of patients with DLB — the second most common cause of degenerative dementia in the elderly after Alzheimer's — had previously suffered from adult ADHD" says lead author Dr Angel Golimstok. "This was more than three times the 15 per cent rate found in both the control group and the group with Alzheimer's.

"DLB is thought to account for around ten per cent of dementia cases in older people, but it tends to be under-diagnosed because it shares some characteristics with both Alzheimer's and Parkinson's.

"It is a degenerative neurological condition that has a progressive and disabling effect on a person's mental and physical skills. Other symptoms can include recurrent and realistic visual hallucinations, fluctuations in the person's everyday abilities and spontaneous movement problems similar to those observed in Parkinson's.

"ADHD is one of the most common behaviour disorders in child and adolescent psychiatry and the problems it causes, such as difficulty paying attention, hyperactivity and doing things impulsively, can continue into adulthood.

"It is believed that the same neurotransmitter pathway problems are involved in the development of both conditions, so our research set out to test the theory that adult ADHD often precedes DLB."

The average age of the study subjects was 75 in the DLB group and 74 in the Alzheimer's and control groups. Approximately two-third of the participants were female and length of education was very similar. None of the patients were taking psychostimulant drugs.

Patient selection was restricted to people with mild to moderate dementia, measuring 14 to 26 on the mini mental status examination scale and one to two on the clinical dementia rating scale.

In the healthy controls, previous ADHD symptoms were assessed using information from the subjects and direct informants. In patients with cognitive impairment, the assessment was based on symptoms described by direct informants who had known the patient for at least 10 years and had information obtained from a close relative who knew the patient in childhood.

Two neurologists, who were unaware of the objectives of the study, were independently asked to assess all the patients for adult ADHD using:

• the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), which has been produced by the American Psychiatric Association to diagnose psychiatric disorders
• the validated Wender Utah Rating Scale, which is specially designed to retrospectively assess ADHD.

This produced agreement levels of 98 per cent in the DLB group, 96 per cent in the Alzheimer's group and 97.5 per cent in the control group.

A third neurologist provided their judgement in the small number of cases where the first two disagreed and a diagnosis of ADHD was recorded if two out of the three neurologists agreed. The results were then checked by a fourth neurologist fully informed about the objectives of the study.

These results provided an overall diagnosis of previous adult ADHD for the two dementia groups and the control. They also showed that impulsivity and hyperactivity, which are major symptoms of ADHD, were significantly higher in the DLB group than the Alzheimer's group and the control group (measuring 14.7, 5.9 and 6.4 respectively on the Wender Utah Rating Scale).

"We believe that our study is the first of its kind to examine the clinical association between adult ADHD symptoms and DLB and that it has established a clear link between the two conditions" says Dr Golimstok.

"Our theory is that this association can be explained by the common neurotransmitter dysfunction present in both conditions. There is clearly a common process involved in both illnesses and it appears that ADHD often develops into DLB as the patient ages."

A new study in the March 1 issue of the journal SLEEP indicates that the ability of children with attention deficit hyperactivity disorder to remain vigilant and attentive deteriorated significantly after losing less than one hour of nightly sleep for a week. The study suggests that even moderate reductions in sleep duration can affect neurobehavioral functioning, which may have a negative impact on the academic performance of children with ADHD.

Results of multivariate analyses of variance show that after mean nightly sleep loss of about 55 minutes for six nights, the performance of children with ADHD on a neurobehavioral test deteriorated from the subclinical range to the clinical range of inattention on four of six measures, including omission errors (missed targets) and reaction time. Children with ADHD generally committed more omission errors than controls. Although the performance of children in the control group also deteriorated after mean nightly sleep loss of 34 minutes for six nights, it did not reach a clinical level of inattention on any of the six measures.

"Moderate sleep restriction leads to a detectable negative impact on the neurobehavioral functioning of children with ADHD and healthy controls, leading to a clinical level of impairment in children with ADHD," said lead author and principal investigator Reut Gruber, PhD, assistant professor in the department of psychiatry at McGill University and director of the Attention, Behavior and Sleep Laboratory at Douglas Mental Health University Institute in Montreal, Québec.

The National Institute of Mental Health reports that ADHD is one of the most common childhood disorders and is characterized by inattention, hyperactivity and impulsivity. To be diagnosed with the disorder, a child must have symptoms for 6 months or more and to a degree that is greater than other children of the same age.

The study involved 43 children, 11 with ADHD and 32 controls. They had a mean age of about 9 years. After their baseline sleep was monitored for six nights, children were asked to eliminate one hour of nightly sleep for six consecutive nights by going to sleep one hour later than usual.

During the baseline and experimental periods, sleep was monitored at home using an actigraph, a computerized device that looks like a wristwatch. Mean nightly sleep time dropped from 487.75 minutes at baseline to 433.07 minutes for the ADHD group, and from 478.81 minutes at baseline to 444.67 minutes for the control group.

"The reduction in sleep duration in our study was modest and similar to the sleep deprivation that might occur in daily life," Gruber said. "Thus, even small changes in dinner time, computer time, or staying up to do homework could result in poorer neurobehavioral functioning the following day and affect sustained attention and vigilance, which are essential for optimal academic performance."

Neurobehavioral functioning was measured with the Continuous Performance Test at the end of the baseline period and following the experimental period of sleep loss. The CPT is a standardized, computer-administered test that takes about 15 minutes to complete. Single letters are presented on a computer screen at three different rates, requiring participants to press a button in response to every signal except the target signal. According to the authors, in recent years the CPT increasingly has been included in the basic neurobehavioral battery administered for ADHD evaluation.

Gruber added that the problem of inadequate sleep in students needs to be prioritized and addressed by the educational system.

"An important implication of the present study is that investments in programs that aim to decrease sleep deprivation may lead to improvements in neurobehavioral functioning and academic performance," she said.

Currently she and her research team are implementing the "Sleep for Success" program in elementary schools in Québec. The program provides tools to help classroom teachers, students and parents reduce sleep deprivation in children and adolescents.

The study was supported by the Canadi­an Institutes of Health Research (CIHR) and the Fonds de la recherche en santé du Québec (FRSQ).

Journal Reference:

1. Reut Gruber, Sabrina Wiebe, Lisa Montecalvo, Bianca Brunetti, Rhonda Amsel, Julie Carrier. Impact of Sleep Restriction on Neurobehavioral Functioning of Children with Attention Deficit Hyperactivity Disorder. Sleep, Volume 34, Issue 03 [

 Thanks in part to a Norwegian research biobank, researchers have generated important new insight into ADHD and how the condition manifests itself. Among other things, they have found that there is some overlap between ADHD and bipolar disorders with regard to rapid mood swings.

Attention deficit hyperactivity disorder (ADHD) occurs on a worldwide basis and appears to affect two to five per cent of the population, depending on the method of measurement used and the population groups examined. Although the condition has been recognised for over 100 years, insight into its causes, prevention and treatment remains limited.

In 2005, a long-term, interdisciplinary research project on the clinical and biological factors associated with ADHD ("ADHD in Norway: Basic and translational studies") was launched in Bergen with funding from the Research Council's Programme for Mental Health (PSYKISK). An extensive international collaboration has been established to follow up the research results in the coming years.

A research biobank containing clinical informational and biological samples from Norwegian ADHD patients and their families, as well as from control subjects, was established as well. Using this data as a basis, the researchers have sought to map the connection between ADHD symptoms and other mental disorders.

Mood swings

"One of our findings is that there is some overlap between AHDH and bipolar disorders with regard to rapid mood swings. It is now being discussed whether mood swings should be included in the official diagnosis criteria for ADHD," explains Jan Haavik, project manager and professor at Haukeland University Hospital and the University of Bergen.

The researchers have also shown that the Norwegian population has many genetic variants that regulate the synthesis of the pheromones dopamine and serotonin. Some of these genetic variants are associated with ADHD symptoms.

Two research studies published February 14 in Neurology®, the medical journal of the American Academy of Neurology, found markers for measuring the ability of children with Attention Deficit Hyperactivity Disorder (ADHD) to control impulsive movements, which may reveal insights into the neurobiology of ADHD, inform prognosis and guide treatments.

In one of two studies conducted by researchers at the Kennedy Krieger Institute in Baltimore, MD and the Cincinnati Children's Hospital Medical Center, children with ADHD performed a finger-tapping task. Any unintentional "overflow" movements occurring on the opposite hand were noted. Children with ADHD showed more than twice the amount of overflow than typically developing children. This is the first time that scientists have been able to quantify the degree to which ADHD is associated with a failure in motor control.

The single most common child behavioral diagnosis, ADHD is a highly prevalent developmental disorder characterized by inattentiveness, hyperactivity and impulsivity. The approximately 2 million affected children often fall behind their peers in development of motor control, motor overflow (unintentional movement) and balance. The inability to control or inhibit voluntary actions is suspected to contribute to the core diagnostic features of excessive hyperactivity, impulsivity and off-task (distractible) behavior.

"Despite its prevalence, there is a lack of understanding about the neurobiological basis of ADHD," said Dr. Stewart Mostofsky, the study's senior author and Director of the Laboratory for Neurocognitive and Imaging Research at the Kennedy Krieger Institute. "A critical obstacle in ADHD is the lack of quantitative measures of brain function that would provide a basis for more accurate diagnosis and effective treatment."

In the study, researchers looked at 50 right-handed children — 25 with ADHD and 25 typically developing, ages 8-12 years. Each subject completed five tasks of sequential finger-tapping on each hand. In this exercise, the children tapped each finger to the thumb of the same hand, in sequence. The tapping hand alternated between left-handed finger sequencing and right-handed finger sequencing. Excessive mirror overflow, defined as unintentional and unnecessary movements occurring in the same muscles on the opposite side of the body, were measured using video and a device that recorded finger position. These methods provided precise quantification of the amount of overflow movement, a major advance over prior studies that relied on qualitiative scales. During left-handed finger tapping, children with ADHD showed more than twice as much mirror overflow than typically developing children. The differences were particularly prominent for boys with ADHD who showed nearly four times as much mirror overflow than typically developing boys on one of the two measures used in the study.

"This study used quantitative measures to support past qualitative findings that motor overflow persists to a greater degree in children with ADHD than in typically developing peers," said Dr. Mostofsky. "The findings reveal that even at an unconscious level, these children are struggling with controlling and inhibiting unwanted actions and behavior. Studying motor control weakness gives us a window to understanding the similar challenges that children with ADHD face in controlling more complex behavior, which can lead to improved diagnosis and treatment."

In a second study, the researchers investigated motor control in children with ADHD further by measuring activity within the motor cortex, the part of the brain that controls voluntary movement. Researchers used Transcranial Magnetic Stimulation (TMS) to apply mild magnetic pulses for brief durations to trigger muscle activity in the hand, causing hand twitches. Researchers performed 60 trials, with single or paired pulses to measure the level of muscle activity and monitored the resulting brain activity, called short interval cortical inhibition (SICI). Overall, children with ADHD showed a substantial decrease in SICI, with significantly less inhibition of motor activity during the paired pulse stimulation compared to typically developing children. The degree of inhibition in children with ADHD, measured by SICI, was 40 percent less than typically developing children. Furthermore, within the ADHD group, less motor inhibition (decreased SICI) correlated with more severe symptoms. The measure of SICI not only predicted motor impairment in ADHD children but also robustly predicted their behavioral symptoms as reported by parents. The findings suggest that reduced SICI may be a critical biomarker of ADHD.

"The neurobiological underpinnings of motor delays and behavioral symptoms in ADHD are not well understood," said Dr. Donald Gilbert, study author and Director of the Transcranial Magnetic Stimulation Laboratory at the Cincinnati Children's Hospital Medical Center. "However, our study provides more insight into the physiological measures of this disorder. We found SICI to be an important biomarker for predicting ADHD symptoms and severity, and it is a highly quantifiable and reproducible measure. This offers a foundation for determining which children are at higher risk for severe and ongoing symptoms as they grow older."

These studies were principally supported by grants from the National Institutes of Health.

Journal References:

1. D. Gilbert, K. Isaacs, M. Augusta, L. Macneil and S. Mostofsky. A marker of ADHD behavior and motor development in children. Neurology, February 15, 2011 vol. 76 no. 7 615-621 DOI: 10.1212/WNL.0b013e31820c2ebd
2. L. Macneil, P. Xavier, M. Garvey, D. Gilbert, M. Ranta, M. Denckla, and S. Mostofsky. Quantifying excessive mirror overflow in children with attention-deficit/hyperactivity disorder. Neurology, February 15, 2011 vol. 76 no. 7 DOI: 10.1212/WNL.0b013e31820c3052

Children with attention-deficit hyperactivity disorder are two to three times more likely than children without the disorder to develop serious substance abuse problems in adolescence and adulthood, according to a study by UCLA psychologists and colleagues at the University of South Carolina.

"This greater risk for children with ADHD applies to boys and girls, it applies across race and ethnicity — the findings were very consistent," said Steve S. Lee, a UCLA assistant professor of psychology and lead author of the study. "The greater risk for developing significant substance problems in adolescence and adulthood applies across substances, including nicotine, alcohol, marijuana, cocaine and other drugs."

Lee and his colleagues analyzed 27 long-term studies that followed approximately 4,100 children with ADHD and 6,800 children without the disorder into adolescence and young adulthood — in some cases for more than 10 years. These carefully designed, rigorous and lengthy studies, Lee said, are the "gold standard" in the field.

The research by Lee and his colleagues, the first large-scale comprehensive analysis on this issue, is published online this week in the journal Clinical Psychology Review and will appear in a print edition later this year.

The researchers combined all the published studies that met rigorous criteria and analyzed them together. They found that children with ADHD were at greater risk for serious problems such as addiction, abuse and trying to quit but being unable to, Lee said.

"Any single study can be spurious," he said, "but our review of more than two dozen carefully designed studies provides a compelling analysis."

ADHD is common, occurring in approximately 5 percent to 10 percent of children in the U.S., and figures in many other industrialized countries with compulsory education are comparable, according to Lee.

Symptoms of the disorder are common in children and include being easily distracted, fidgeting, being unable to complete a single task and being easily bored. However, to receive a diagnosis of ADHD, a child must have at least six of nine symptoms of either hyperactivity or inattention, and the child's behavior must be causing problems in his or her life. The vast majority of children with ADHD have at least six symptoms in both categories, Lee said.

In addition, the symptoms must have started before age seven, must be present in multiple settings — at home and school, for example — and must be adversely affecting functioning. They must not be explainable by any medical condition or any other mental disorder.

As children with ADHD enter adolescence and adulthood, they typically fall into three groups of roughly equal size, Lee said: one-third will have significant problems in school and socially; one-third will have moderate impairment; and one-third will do reasonably well or have only mild impairment.

Parents should monitor their children, said Lee, who noted that early intervention with a mental health professional is often helpful. A diagnosis of ADHD must be made by a mental health professional such as a child psychologist or psychiatrist and not by a parent or teacher.

Co-authors on the study are Kathryn Humphreys, a UCLA graduate student in clinical psychology; Kate Flory, an assistant professor of psychology at the University of South Carolina; Rebecca Liu, a UCLA undergraduate who worked in Lee's laboratory; and Kerrie Glass, a graduate student in psychology at the University of South Carolina.

The research was federally funded by the National Institutes of Health's National Institute on Alcohol Abuse and Alcoholism.

Journal Reference:

1. Steve S. Lee, Kathryn L. Humphreys, Kate Flory, Rebecca Liu, Kerrie Glass. Prospective Association of Childhood Attention-deficit/hyperactivity Disorder (ADHD) and Substance Use and Abuse/Dependence: A Meta-Analytic Review☆. Clinical Psychology Review, 2011; DOI: 10.1016/j.cpr.2011.01.006