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ADHD
New Insight Into ADHD
ScienceDaily (Mar. 1, 2011) — 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.
ADHD Linked To Sleep Problems In Adolescents
ScienceDaily (May 1, 2009) — A new study shows that adolescents with a
childhood diagnosis of Attention Deficit/Hyperactivity Disorder (ADHD) are
more likely to have current and lifetime sleep problems and disorders,
regardless of the severity of current ADHD symptoms. Authors suggest that
findings indicate that mental health professionals should screen for sleep
problems and psychiatric comorbidities among all adolescents with a
childhood diagnosis of ADHD.
Results indicate that adolescents with a childhood diagnosis of ADHD, regardless of persistent ADHD
were more likely to have current sleep problems and sleep disorders such as insomnia, sleep terrors,
nightmares, bruxism and snoring. Of the total sample, 17 percent of children with ADHD were
currently suffering from primary insomnia, versus 7 percent of controls; lifetime primary insomnia
occurred in 20 percent of children with ADHD, compared to 10 percent of controls. Nightmare disorder
affected 11 percent of children with ADHD and lifetime nightmare disorder affected 23 percent, versus
5 and 16 percent of controls. The presence of at least one psychiatric comorbid condition increases
the risks for insomnia and nightmares.
According to principal investigator Susan Shur-Fen Gau, MD, PhD, associate professor at the College
of Medicine and Public Health, National Taiwan University, symptoms and consequences of ADHD
and sleep problems in children often overlap. Some primary sleep disorders are found to be
associated with inattention, hyperactivity, behavioral problems and impaired academic performance,
which are often mistaken for symptoms of ADHD.
"In some patients with ADHD, symptoms are caused or exaggerated by primary sleep disorders, and
therefore treatment of the sleep disorder will improve ADHD symptoms," said Gau.
Data were collected from 281 consecutive patients (86.2 percent male) between the ages of 10 to 17
years who had been diagnosed with ADHD according to DSM-IV criteria at a mean age of 6.7 years,
and 185 controls who did not have ADHD as a child or teen. Diagnosis of ADHD was made based on
information obtained from parent and child interviews, observation of the child's behaviors, and rating
scales reported by parents and teachers.
Findings of the study indicated that the rates of nightmare and lifetime nightmare disorder were more
prevalent in girls and snoring was more prevalent in boys. Snoring may be more prevalent in boys
due to an increased rate of sleep-disordered breathing in boys. Mothers were found to be more aware
of symptoms related to ADHD in the presence of primary insomnia, sleep terror disorder or
sleepwalking disorder, whereas teachers may be more sensitive to ADHD symptoms in the presence
of primary hypersomnia and nightmare disorder.
According to the study, sleep problems in children with ADHD may be caused by a variety of factors,
including internet addiction, hyperactivity, use of stimulants and the presence of other psychiatric
disorders. Authors of the study state that the etiology of sleep problems and disorders need to be
identified in children with ADHD, in order to create a modified treatment regime for sleep disorders
and ADHD symptoms.
Sleep Problems Common In Children With ADHD, Study Shows
ScienceDaily (Apr. 7, 2008) — Children with attention-deficit/hyperactivity
disorder (ADHD) appear likely to experience sleep problems, according to
a new report. Sleep problems in these children may be associated with
poorer child psychosocial quality of life, child daily functioning, caregiver
mental health and family functioning.
Attention-deficit/hyperactivity disorder is a behavioral disorder, usually first diagnosed in childhood,
that is characterized by inattention, impulsivity and hyperactivity. "ADHD is the most common mental
health disorder in childhood, affecting up to 11 percent of Australians aged 6 to 17 years," according
to background information in the article. About half of parents of children with ADHD report that their
children have difficulty sleeping, feel tired on waking or have nightmares or other sleep problems such
as disordered breathing and restless leg syndrome. Parents of children with ADHD are more likely to
experience stress, anxiety and depression than those of children without ADHD.
Valerie Sung, M.B.B.S., of the Centre for Community Child Health, Parkville, Australia, and
colleagues studied families of 239 schoolchildren (average age 11.7) with ADHD to determine the
prevalence and broad effects of sleep problems in these children. The association of sleep problems
with child health-related quality of life, daily functioning, school attendance, primary caregiver mental
health and work attendance and family impacts were also noted.
Sleep problems affected 175 (73.3 percent) of the children, with a 28.5 percent prevalence of mild
sleep problems and 44.8 percent prevalence of moderate or severe sleep problems. Some of the
most commonly occurring sleep patterns were difficulty falling asleep, resisting going to bed and
tiredness on waking.
"Compared with children without sleep problems, those with sleep problems were more likely to miss
or be late for school, and their caregivers were more likely to be late for work," the authors write.
"Forty-five percent of caregivers reported that their pediatricians had asked about their children's
sleep and, of these, 60 percent reported receiving treatment advice."
"In summary, sleep problems in schoolchildren with ADHD are extremely common and strongly
associated with poorer quality of life, daily functioning and school attendance in the child and poorer
caregiver mental health and work attendance," the authors conclude. "Implementation of a sleep
intervention in children with ADHD could feasibly improve outcomes beyond treatment of ADHD
alone. It is possible that such intervention could reduce the need for medication in some children."
"In the meantime, clinicians caring for children with ADHD should ask about their sleep, and if a
problem is present, this should be addressed."
Journal reference: Arch Pediatr Adolesc Med. 2008;162[4]:336-342.
Underlying Sleep Problem Linked To AttentionDeficit/hyperactivity Disorder In Children
ScienceDaily (Mar. 1, 2009) — A study in the March 1 issue of the journal
SLEEP suggests the presence of an intrinsic sleep problem specific to
attention-deficit/hyperactivity disorder (ADHD) and supports the idea that
children with ADHD may be chronically sleep deprived and have abnormal
REM sleep.
Results show that children with ADHD have a total sleep time that is significantly shorter than that of
controls. Children in the ADHD group had an average total sleep time of eight hours, 19 minutes; this
was 33 minutes less than the average sleep time of eight hours, 52 minutes, in controls. Children with
ADHD also had an average rapid eye movement (REM) sleep time that was significantly reduced by
16 minutes.
According to the principal investigator and the lead author, Reut Gruber, PhD, director of the
Attention, Behaviour and Sleep Lab at the Douglas Mental Health University Institute, results of the
study were encouraging, as the researchers were able to control for many confounding factors, which
reduced some of the confusion and contradictions discovered in previous studies. Measuring sleep
architecture in the children's beds at home using portable PSG, also allowed researchers to better
represent the natural sleep pattern, thus increasing the validity of the study.
"I do not believe that sleep per se is the cause of ADHD, but it may make the symptoms worse in
children with sleep problems. There are reports in the literature in which treating sleep problems led to
improvement in ADHD symptoms but I suspect that these results were seen in children with sleep
apnea. More research needs to be done in order to determine if sleep affects ADHD children with no
primary sleep disorder."
According to the authors, ADHD is one of the most prevalent conditions in child psychiatry, and 25
percent to 50 percent of children and adolescents diagnosed with the disorder have clinically reported
sleep problems. Partial sleep loss on a chronic basis accumulates to become a sleep debt, which can
produce significant daytime sleepiness and neurobehavioral impairment. Studies also have shown
that disrupted sleep can affect daytime learning and attention in childhood and can lead to ADHD-like
symptoms.
Portable polysomnography sleep recorders were used to perform overnight sleep recordings on 15
children diagnosed with ADHD without comorbid psychiatric problems, and on 23 healthy controls.
The children were between the ages of 7 and 11, were not taking medication and were instructed to
avoid products containing caffeine for at least seven days leading up to the overnight sleep study,
which was performed in each child's home.
Parents completed the Child Behavioral Checklist, a 113-item questionnaire assessing behavioral and
emotional problems. Children also were assessed for pubertal development. Factors such as age,
sex, gender, socioeconomic status and parents' marital status were controlled.
According to the authors, this study may suggest that ADHD children suffer from an intrinsic sleep
problem that could be related to the underlying pathophysiology of the disorder. They report that the
impact of sleep duration on neuropsychological functioning in children with ADHD should be
investigated further. Additional studies also will be required to examine whether shorter sleep duration
in children with ADHD is associated with ADHD-like symptoms, including behavioral problems and
poor neurocognitive functioning. The authors suggest that if a functional alteration of sleep in children
with ADHD can be confirmed, then it may be possible to develop therapeutic approaches for
optimizing and individualizing the children's sleep regimes.
First Direct Evidence That ADHD Is a Genetic Disorder:
Children With ADHD More Likely to Have Missing or Duplicated
Segments of DNA
ScienceDaily (Sep. 29, 2010) — New research provides the first direct
evidence that attention-deficit/hyperactivity disorder (ADHD) is a genetic
condition. Scientists at Cardiff University found that children with ADHD
were more likely to have small segments of their DNA duplicated or missing
than other children.
The study also found significant overlap between these segments, known as copy number variants
(CNVs), and genetic variants implicated in autism and schizophrenia, proving strong evidence that
ADHD is a neurodevelopmental disorder -- in other words, that the brains of children with the disorder
differ from those of other children.
The research, published in the journal The Lancet, was largely funded by the Wellcome Trust, with
additional support from Action Medical Research, the Medical Research Council and the European
Union.
"We hope that these findings will help overcome the stigma associated with ADHD," says Professor
Anita Thapar. "Too often, people dismiss ADHD as being down to bad parenting or poor diet. As a
clinician, it was clear to me that this was unlikely to be the case. Now we can say with confidence that
ADHD is a genetic disease and that the brains of children with this condition develop differently to
those of other children."
ADHD is one of the most common mental health disorders in childhood, affecting around one in 50
children in the UK. Children with ADHD are excessively restless, impulsive and distractible, and
experience difficulties at home and in school. Although no cure exists for the condition, symptoms can
be reduced by a combination of medication and behavioural therapy.
The condition is highly heritable -- children with ADHD are statistically more likely to also have a
parent with the condition and a child with an identical twin with ADHD has a three in four chance of
also having the condition. Even so, until now there has been no direct evidence that the condition is
genetic and there has been much controversy surrounding its causes, which some people have put
down to poor parenting skills or a sugar-rich diet.
The team at Cardiff University analysed the genomes of 366 children, all of whom had been given a
clinical diagnosis of ADHD, against over 1,000 control samples in search of variations in their genetic
make-up that were more common in children with the condition.
"Children with ADHD have a significantly higher rate of missing or duplicated DNA segments
compared to other children and we have seen a clear genetic link between these segments and other
brain disorders," explains Dr Nigel Williams. "These findings give us tantalising clues to the changes
that can lead to ADHD."
The researchers found that rare CNVs were almost twice as common in children with ADHD
compared to the control sample -- and even higher for children with learning difficulties. CNVs are
particularly common in disorders of the brain.
There was also significant overlap between CNVs identified in children with ADHD and regions of the
genome which are known to influence susceptibility to autism and schizophrenia. Whilst these
disorders are currently thought to be entirely separate, there is some overlap between ADHD and
autism in terms of symptoms and learning difficulties. This new research suggests there may be a
shared biological basis to the two conditions.
The most significant overlap was found at a particular region on chromosome 16 which has been
previously implicated in schizophrenia and other major psychiatric disorders and spans a number of
genes including one known to play a role in the development of the brain .
"ADHD is not caused by a single genetic change, but is likely caused by a number of genetic
changes, including CNVs, interacting with a child's environment," explains Dr Kate Langley.
"Screening children for the CNVs that we have identified will not help diagnose their condition. We
already have very rigorous clinical assessments to do just that."
Dr John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust, which has
supported Professor Thapar's work for ten years, says: "These findings are testament to the
perseverance of Professor Thapar and colleagues to prove the often unfashionable theory that ADHD
is a brain disorder with genetic links. Using leading-edge technology, they have begun to shed light on
the causes of what is a complex and often distressing disorder for both the children and their
families."
American Academy of Pediatrics Expands Ages for Diagnosis
and Treatment of ADHD in Children
ScienceDaily (Oct. 16, 2011) — Updated guidelines from the American
Academy of Pediatrics (AAP) offer new information on diagnosing and
treating Attention-Deficit/Hyperactivity Disorder (ADHD) in younger children
and in adolescents.
Emerging evidence makes it possible to diagnose and manage ADHD in children from ages 4 to 18
(the previous AAP guidelines, from 2000 and 2001, covered children ages 6 to 12). The new
guidelines describe the special considerations involved in diagnosing and treating preschool children
and adolescents. They also include interventions to help children with hyperactive/impulsive
behaviors that do not meet the full diagnostic criteria for ADHD.
"Treating children at a young age is important, because when we can identify them earlier and provide
appropriate treatment, we can increase their chances of succeeding in school," said Mark Wolraich,
MD, FAAP, lead author of the report. "Because of greater awareness about ADHD and better ways of
diagnosing and treating this disorder, more children are being helped."
ADHD is the most common neurobehavioral disorder in children, occurring in about 8 percent of
children and youth.
The report, "ADHD: Clinical Practice Guidelines for the Diagnosis, Evaluation and Treatment of
Children and Adolescents with Attention-Deficit/Hyperactivity Disorder," will be released on October
16, at the AAP National Conference & Exhibition in Boston, and will be published in the November
2011 issue of Pediatrics (published online Oct. 16).
According to the AAP guidelines, in preschool children (ages 4 and 5) with ADHD, doctors should first
try behavioral interventions, such as group or individual parent training in behavior management
techniques. Methylphenidate may be considered for preschool children with moderate to severe
symptoms who do not see significant improvement after behavior therapy, starting with a lower dose.
For elementary school children and adolescents, the AAP recommends both FDA-approved
medications and behavior therapy.
"Because ADHD is a chronic condition, it requires a team approach, including the patients, their
parents, the pediatrician, therapists, and teachers," Dr. Wolraich said.
In addition to the formal recommendations for assessment, diagnosis and treatment of ADHD, the
guidelines provide a single algorithm to guide the clinical process. The AAP is also releasing a newly
revised and updated ADHD Toolkit to assist health care providers diagnose and treat ADHD in their
patients. To help parents understand the new guidance on ADHD, the AAP has published a detailed
and updated consumer resource book entitled "ADHD: What Every Parent Needs to Know."
Is ADHD More Likely To Affect Movement In Boys Or Girls?
ScienceDaily (Nov. 3, 2008) — Attention deficit hyperactivity disorder
(ADHD) appears to affect movement in boys more than it does in girls,
according to a new study. ADHD is one of the most common mental
disorders found in children. Symptoms include impulsiveness, hyperactivity,
such as not being able to sit still, and inattention or constant daydreaming.
Few studies have been done that compare ADHD and movement in both
boys and girls.
Researchers tested the movement abilities of 132 boys and girls with ADHD and 136 without the
disorder. The children were between the ages of seven and 15 years and were tested for how fast
and how well they could tap their toes, walk on their heels, maintain balance and keep a steady
rhythm during a task compared to scores typical for their age.
The study found that girls with ADHD and the control group of children without ADHD were twice as
likely to be able to control their movements for their age compared to boys with ADHD, who showed
continued difficulties.
"Our findings suggest that the differences between boys and girls with ADHD show up not only in
behavior and symptoms but also in development of movement control, likely because girls' brains
mature earlier than boys' brains," said study author E. Mark Mahone, PhD, with the Kennedy Krieger
Institute and Johns Hopkins University School of Medicine in Baltimore, MD.
"More studies related to ADHD and movement are needed that look at boys and girls separately and
at younger ages," said Mahone.
These research was published in the November 4, 2008, issue of Neurology®, the medical journal of
the American Academy of Neurology.
The study was supported by the National Institute of Neurological Disorders and Stroke, Kennedy
Krieger Institute's Developmental Disabilities Research Center and the Johns Hopkins University
School of Medicine Institute for Clinical and Translational Research.
Functional Brain Pathways Disrupted in Children With ADHD
ScienceDaily (Nov. 28, 2011) — 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, according to a study presented November
28 at the annual meeting of the Radiological Society of North America
(RSNA).
ADHD is one of the most common childhood disorders, affecting an estimated five to eight percent of
school-aged children. Symptoms, which may continue into adulthood, include inattention,
hyperactivity and impulsivity behaviors that are out of the normal range for a child's age and
development.
According to the National Institute of Mental Health, there is no single test capable of diagnosing a
child with the disorder. As a result, difficult children are often incorrectly labeled with ADHD while
other children with the disorder remain undiagnosed.
"Diagnosing ADHD is very difficult because of its wide variety of behavioral symptoms," said lead
researcher Xiaobo Li, Ph.D., assistant professor of radiology at the Albert Einstein College of
Medicine in New York. "Establishing a reliable imaging biomarker of ADHD would be a major
contribution to the field."
For the study, Dr. Li and colleagues performed fMRI on 18 typically developing children and 18
children diagnosed with ADHD (age range 9 to 15 years). While undergoing fMRI, the children
engaged in a test of sustained attention in which they were shown a set of three numbers and then
asked whether subsequent groups of numbers matched the original set. For each participant, fMRI
produced a brain activation map that revealed which regions of the brain became activated while the
child performed the task. The researchers then compared the brain activation maps of the two groups.
Compared to the normal control group, the children with ADHD showed abnormal functional activity in
several regions of the brain involved in the processing of visual attention information. The researchers
also found that communication among the brain regions within this visual attention-processing
pathway was disrupted in the children with ADHD.
"What this tells us is that children with ADHD are using partially different functional brain pathways to
process this information, which may be caused by impaired white matter pathways involved in visual
attention information processing," Dr. Li said.
Dr. Li said much of the research conducted on ADHD has focused on the impulsivity component of
the disorder.
"Inattention is an equally important component of this disorder," she said, "and our findings contribute
to understanding the pathology of inattentiveness in ADHD."
Coauthors are Shugao Xia, Ariane Kimball and Craig Branch, Ph.D.