Pattern Recognition Technology May Help Predict Future Mental Illness in Teens

Pattern Recognition Technology May Help Predict Future Mental Illness in Teens


Source: NIMH

A technique combining computer-based pattern recognition and brain imaging data accurately distinguished teens at risk for mental disorders from those with low risk and may someday be useful in predicting risk in individuals, according to an NIMH-funded study published February 15, 2012, in the journal PLoS One.

Background

Research on risk for mental disorders generally describes risk factors that apply to groups. To date, no biological measures can accurately predict an individual’s risk of future mental disorders.

Mary Phillips, M.D., of the University of Pittsburgh School of Medicine, and colleagues evaluated the use of computer-based techniques that automatically find patterns in data—these techniques are collectively called machine learning—with functional magnetic resonance imaging (fMRI) data. The researchers obtained fMRI data from 32 teens, half of whom had at least one biological parent diagnosed with bipolar disorder and were therefore at genetic risk for future psychiatric disorders. The other half of teens had no history of mental disorders either personally or in their immediate families.

The teens’ brain activity was assessed as they identified the gender of actors depicting various emotional facial expressions (happy, fearful, or neutral) in a series of photographs. Previous research has linked various mental disorders, especially depression and bipolar disorder, with abnormal patterns of brain activity during this task. Based on this fMRI data, the researchers used machine learning to calculate each participant’s odds for future mental illness social worker ceus

The participants were also assessed clinically and with fMRI at the start of the study, and clinically assessed again about two years later, on average. Long-term follow up is ongoing, with successive face-to-face assessments occurring every other year.

Results

Machine learning combined with fMRI accurately identified most of the healthy teens at genetic risk of future mental disorders vs. healthy teens with low genetic risk. Four of the 16 at-risk teens were misidentified as having low risk.

At the two-year follow up, none of the at-risk teens had developed bipolar disorder, but six were diagnosed with major depression or an anxiety disorder. Among all the at-risk teens identified through machine learning, these six had received the highest odds for belonging to the at-risk group.

Three of the four at-risk teens misidentified as belonging to the low risk group at the start of the study remained healthy at the second assessment. Clinical information for the fourth teen was not available at the time of follow-up.

Significance

Though still a very preliminary study, according to the researchers, machine learning combined with fMRI shows promise for predicting individual risk of developing future mental disorders, especially in at-risk populations.

The ongoing follow-up may also yield further insights into the relationship between depression, anxiety disorders, and bipolar disorder. Many studies have shown that bipolar disorder is often preceded by depression or anxiety disorders, and that these disorders may affect the course of subsequent bipolar disorder.

What’s Next

Larger studies using machine learning and fMRI will help to better define the extent to which pattern recognition techniques can accurately identify people at risk for future mental disorders. Research in this area may also inform early treatment or prevention efforts.

Reference

Mourão-Miranda J, Oliveira L, Ladouceur CD, Marquand A, Brammer M, Birmaher B, Axelson D, Phillips ML. Pattern recognition and functional neuroimaging help to discriminate healthy adolescents at risk for mood disorders from low risk adolescents. PLoS One. 2012;7(2):e29482. Epub 2012 Feb 15. PubMed PMID: 22355302; PubMed Central PMCID: PMC3280237.

Related Funding: K01 MH083001-04; R01 MH060952-11

Brain Wiring a No-Brainer?

The brain appears to be wired more like the checkerboard streets of New York City than the curvy lanes of Columbia, Md., suggests a new brain imaging study. The most detailed images, to date, reveal a pervasive 3D grid structure with no diagonals, say scientists funded by the National Institutes of Health.

“Far from being just a tangle of wires, the brain’s connections turn out to be more like ribbon cables -- folding 2D sheets of parallel neuronal fibers that cross paths at right angles, like the warp and weft of a fabric,” explained Van Wedeen, M.D., of Massachusetts General Hospital (MGH), A.A. Martinos Center for Biomedical Imaging and the Harvard Medical School. “This grid structure is continuous and consistent at all scales and across humans and other primate species.”

Wedeen and colleagues report new evidence of the brain’s elegant simplicity March 30, 2012 in the journal Science. The study was funded, in part, by the NIH’s National Institute of Mental Health (NIMH), the Human Connectome Project of the NIH Blueprint for Neuroscience Research, and other NIH components.

“Getting a high resolution wiring diagram of our brains is a landmark in human neuroanatomy,” said NIMH Director Thomas R. Insel, M.D. “This new technology may reveal individual differences in brain connections that could aid diagnosis and treatment of brain disorders.”

Knowledge gained from the study helped shape design specifications for the most powerful brain scanner of its kind, which was installed at MGH’s Martinos Center last fall. The new Connectom diffusion magnetic resonance imaging (MRI) scanner can visualize the networks of crisscrossing fibers – by which different parts of the brain communicate with each other – in 10-fold higher detail than conventional scanners, said Wedeen.

“This one-of-a-kind instrument is bringing into sharper focus an astonishingly simple architecture that makes sense in light of how the brain grows,” he explained. “The wiring of the mature brain appears to mirror three primal pathways established in embryonic development.”

As the brain gets wired up in early development, its connections form along perpendicular pathways, running horizontally, vertically and transversely. This grid structure appears to guide connectivity like lane markers on a highway, which would limit options for growing nerve fibers to change direction during development. If they can turn in just four directions: left, right, up or down, this may enforce a more efficient, orderly way for the fibers to find their proper connections – and for the structure to adapt through evolution, suggest the researchers.

Obtaining detailed images of these pathways in human brain has long eluded researchers, in part, because the human cortex, or outer mantle, develops many folds, nooks and crannies that obscure the structure of its connections. Although studies using chemical tracers in neural tracts of animal brains yielded hints of a grid structure, such invasive techniques could not be used in humans.

Wedeen’s team is part of a Human Connectome Project Harvard/MGH-UCLA consortium that is optimizing MRI technology to more accurately to image the pathways. In diffusion imaging, the scanner detects movement of water inside the fibers to reveal their locations. A high resolution technique called diffusion spectrum imaging (DSI) makes it possible to see the different orientations of multiple fibers that cross at a single location – the key to seeing the grid structure ceus for social workers

In the current study, researchers performed DSI scans on postmortem brains of four types of monkeys – rhesus, owl, marmoset and galago – and in living humans. They saw the same 2D sheet structure containing parallel fibers crossing paths everywhere in all of the brains – even in local path neighborhoods. The grid structure of cortex pathways was continuous with those of lower brain structures, including memory and emotion centers. The more complex human and rhesus brains showed more differentiation between pathways than simpler species.

Among immediate implications, the findings suggest a simplifying framework for understanding the brain’s structure, pathways and connectivity.

The technology used in the current study was able to see only about 25 percent of the grid structure in human brain. It was only apparent in large central circuitry, not in outlying areas where the folding obscures it. But lessons learned were incorporated into the design of the newly installed Connectom scanner, which can see 75 percent of it, according to Wedeen.

Much as a telescope with a larger mirror or lens provides a clearer image, the new scanner markedly boosts resolving power by magnifying magnetic fields with magnetically stronger copper coils, called gradients. Gradients make it possible to vary the magnetic field and get a precise fix on locations in the brain. The Connectom scanner’s gradients are seven times stronger than those of conventional scanners. Scans that would have previously taken hours – and, thus would have been impractical with living human subjects – can now be performed in minutes.

“Before, we had just driving directions. Now, we have a map showing how all the highways and byways are interconnected,” said Wedeen. “Brain wiring is not like the wiring in your basement, where it just needs to connect the right endpoints. Rather, the grid is the language of the brain and wiring and re-wiring work by modifying it.”


Detail from DSI scan shows fabric-like 3D grid structure of connections in monkey brain.

Source: Van Wedeen, M.D., Martinos Center and Dept. of Radiology, Massachusetts General Hospital and Harvard University Medical School


Curvature in this DSI image of a whole human brain turns out to be folding of 2D sheets of parallel neuronal fibers that cross paths at right angles. This picture came from the new Connectom scanner.
Source: Van Wedeen, M.D., Martinos Center and Dept. of Radiology, Massachusetts General Hospital and Harvard University Medical School

Reference

Wedeen VJ, Rosene DL, Ruopeng W, Guangping D, Mortazavi F, Hagmann P, Kass JH, Tseng W-YI. The Geometric Structure of the Brain Fiber Pathways: A Continuous Orthogonal Grid. March 30, 2012 Science.

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The mission of the NIMH is to transform the understanding and treatment of mental illnesses through basic and clinical research, paving the way for prevention, recovery and cure. For more information, visit the NIMH website.

The NIH Blueprint for Neuroscience Research is a cooperative effort among the NIH Office of the Director and the 15 NIH Institutes and Centers that support research on the nervous system. By pooling resources and expertise, the Blueprint supports transformative neuroscience research, and the development of new tools, training opportunities, and other resources to assist neuroscientists.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit the NIH website.

Scripps Research Institute Team Wrests Partial Control of a Memory

News Release

The work advances understanding of how memories form and offers new insight into disorders such as schizophrenia and post traumatic stress disorder

LA JOLLA, CA – March 22, 2012 – Scripps Research Institute scientists and their colleagues have successfully harnessed neurons in mouse brains, allowing them to at least partially control a specific memory. Though just an initial step, the researchers hope such work will eventually lead to better understanding of how memories form in the brain, and possibly even to ways to weaken harmful thoughts for those with conditions such as schizophrenia and post traumatic stress disorder.

The results are reported in the March 23, 2012 issue of the journal Science.

Researchers have known for decades that stimulating various regions of the brain can trigger behaviors and even memories. But understanding the way these brain functions develop and occur normally—effectively how we become who we are—has been a much more complex goal.

“The question we’re ultimately interested in is: How does the activity of the brain represent the world?” said Scripps Research neuroscientist Mark Mayford, who led the new study. “Understanding all this will help us understand what goes wrong in situations where you have inappropriate perceptions. It can also tell us where the brain changes with learning.”

On-Off Switches and a Hybrid Memory

As a first step toward that end, the team set out to manipulate specific memories by inserting two genes into mice. One gene produces receptors that researchers can chemically trigger to activate a neuron. They tied this gene to a natural gene that turns on only in active neurons, such as those involved in a particular memory as it forms, or as the memory is recalled. In other words, this technique allows the researchers to install on-off switches on only the neurons involved in the formation of specific memories.

For the study’s main experiment, the team triggered the “on” switch in neurons active as mice were learning about a new environment, Box A, with distinct colors, smells and textures continuing education for counselors

Next the team placed the mice in a second distinct environment—Box B—after giving them the chemical that would turn on the neurons associated with the memory for Box A. The researchers found the mice behaved as if they were forming a sort of hybrid memory that was part Box A and part Box B. The chemical switch needed to be turned on while the mice were in Box B for them to demonstrate signs of recognition. Alone neither being in Box B nor the chemical switch was effective in producing memory recall.

“We know from studies in both animals and humans that memories are not formed in isolation but are built up over years incorporating previously learned information,” Mayford said. “This study suggests that one way the brain performs this feat is to use the activity pattern of nerve cells from old memories and merge this with the activity produced during a new learning session.”

Future Manipulation of the Past

The team is now making progress toward more precise control that will allow the scientists to turn one memory on and off at will so effectively that a mouse will in fact perceive itself to be in Box A when it’s in Box B.

Once the processes are better understood, Mayford has ideas about how researchers might eventually target the perception process through drug treatment to deal with certain mental diseases such as schizophrenia and post traumatic stress disorder. With such problems, patients’ brains are producing false perceptions or disabling fears. But drug treatments might target the neurons involved when a patient thinks about such fear, to turn off the neurons involved and interfere with the disruptive thought patterns.

In addition to Mayford, other authors of the paper, “Generation of a Synthetic Memory Trace,” are Aleena Garner, Sang Youl Hwang, and Karsten Baumgaertel from Scripps Research, David Rowland and Cliff Kentros from the University of Oregon, Eugene, and Bryan Roth from the University of North Carolina (UNC), Chapel Hill.

This work is supported by the National Institute of Mental Health, the National Institute on Drug Abuse, the California Institute for Regenerative Medicine, and the Michael Hooker Distinguished Chair in Pharmacology at UNC.

About The Scripps Research Institute

The Scripps Research Institute is one of the world's largest independent, non-profit biomedical research organizations. Scripps Research is internationally recognized for its discoveries in immunology, molecular and cellular biology, chemistry, neuroscience, and vaccine development, as well as for its insights into autoimmune, cardiovascular, and infectious disease. Headquartered in La Jolla, California, the institute also includes a campus in Jupiter, Florida, where scientists focus on drug discovery and technology development in addition to basic biomedical science. Scripps Research currently employs about 3,000 scientists, staff, postdoctoral fellows, and graduate students on its two campuses. The institute's graduate program, which awards Ph.D. degrees in biology and chemistry, is ranked among the top ten such programs in the nation. For more information, see www.scripps.edu.

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Friendly-to-a-Fault, Yet Tense: Personality Traits Traced in Brain

Scans Reveal How Genes Alter Circuit Hub to Shape Temperament – NIH Study

A personality profile marked by overly gregarious yet anxious behavior is rooted in abnormal development of a circuit hub buried deep in the front center of the brain, say scientists at the National Institutes of Health. They used three different types of brain imaging to pinpoint the suspect brain area in people with Williams syndrome, a rare genetic disorder characterized by these behaviors. Matching the scans to scores on a personality rating scale revealed that the more an individual with Williams syndrome showed these personality/temperament traits, the more abnormalities there were in the brain structure, called the insula CADC I & II Continuing Education

“Scans of the brain’s tissue composition, wiring, and activity produced converging evidence of genetically-caused abnormalities in the structure and function of the front part of the insula and in its connectivity to other brain areas in the circuit,” explained Karen Berman, M.D., of the NIH’s National Institute of Mental Health (NIMH).

Berman, Drs. Mbemda Jabbi, Shane Kippenhan, and colleagues, report on their imaging study in Williams syndrome online in the journal Proceedings of the National Academy of Sciences.

“This line of research offers insight into how genes help to shape brain circuitry that regulates complex behaviors – such as the way a person responds to others – and thus holds promise for unraveling brain mechanisms in other disorders of social behavior,” said NIMH Director Thomas R. Insel, M.D.

Williams syndrome is caused by the deletion of some 28 genes, many involved in brain development and behavior, in a particular section of chromosome 7. Among deficits characteristic of the syndrome are a lack of visual-spatial ability – such as is required to assemble a puzzle – and a tendency to be overly-friendly with people, while overly anxious about non-social matters, such as spiders or heights. Many people with the disorder are also mentally challenged and learning disabled, but some have normal IQs.

Previous imaging studies by the NIMH researchers found abnormal tracts of the neuronal fibers that conduct long-distance communications between brain regions -- likely resulting from neurons migrating to the wrong destinations during early development.

Evidence suggests that genes influence our temperament and the development of mental disorders via effects on brain circuits that regulate behavior. Yet direct demonstration of this in humans has proven elusive. Since the genetic basis of Williams syndrome is well known, it offers a unique opportunity to explore such effects with neuroimaging, reasoned the researchers.

Although the insula had not previously been studied in such detail in the disorder, it was known to be related to brain circuitry and certain behaviors, such as empathy, which is also highly prominent in the disorder. Berman and colleagues hypothesized that the insula’s anatomy, function and connectivity would predict patients’ scores for Williams syndrome-associated traits on personality rating scales. Fourteen intellectually normal Williams syndrome participants and 23 healthy controls participated in the study.

Magnetic resonance imaging (MRI) revealed that patients had decreased gray matter – the brain’s working tissue – in the bottom front of the insula, which integrates mood and thinking. By contrast, they had increased gray matter in the top front part of the insula, which has been linked to social/emotional processes.

Diffusion tensor imaging, which by detecting the flow of water in nerve fibers can identify and measure the connections between brain areas, showed reduced white matter – the brain’s long-distance wiring – between thinking and emotion hubs.

Tracking radioactively-tagged water in order to measure brain blood flow at rest, via positron emission tomography (PET), exposed activity aberrations consistent with the MRI abnormalities. The PET scans also revealed altered functional coupling between the front of the insula and key structures involved in thinking, mood and fear processing. These structural and functional abnormalities in the front of the insula correlated with the Williams syndrome personality profile.

“Our findings illustrate how brain systems translate genetic vulnerability into behavioral traits,” explained Berman.

The severity of abnormalities in insula (red structure near bottom of brain) gray matter volume (left) and brain activity (right) predicted the extent of aberrant personality traits in Williams syndrome patients – as reflected in their scores (red dots) on personality rating scales (WSPP).

Source: Karen Berman, M.D., NIMH Clinical Brain Disorders Branch


Long distance connections, white matter, between the insula and other parts of the brain are aberrant in Williams syndrome. Neuronal fibers of normal controls (left) extend further than those of Williams syndrome patients (right). Picture shows diffusion tensor imaging data from each patient superimposed on anatomical MRI of the median patient.

Source: Karen Berman, M.D., NIMH Clinical Brain Disorders Branch


Reference:

The Williams syndrome chromosome 7q11.23 hemideletion confers hypersocial, anxious personality coupled with altered insula structure and function. Jabbi M, Kippenhan JS, Kohn P, Marenco S, Mervis CB, Morris CA, Meyer-Lindenberg A, Berman KF. Proc Natl Acad Sci U S A. 2012 Mar 12. [Epub ahead of print] PMID: 22411788

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The mission of the NIMH is to transform the understanding and treatment of mental illnesses through basic and clinical research, paving the way for prevention, recovery and cure. For more information, visit the NIMH website.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit the NIH website.

Possible Causes of Sudden Onset OCD in Kids Broadened

NIH Immune-Based Treatment Study Underway

Criteria for a broadened syndrome of acute onset obsessive compulsive disorder (OCD) have been proposed by a National Institutes of Health scientist and her colleagues. The syndrome, Pediatric Acute-onset Neuropsychiatric Syndrome (PANS), includes children and teens that suddenly develop on-again/off-again OCD symptoms or abnormal eating behaviors, along with other psychiatric symptoms – without any known cause nursing ceus

PANS expands on Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcus (PANDAS), which is limited to a subset of cases traceable to an autoimmune process triggered by a strep infection. A clinical trial testing an immune-based treatment for PANDAS is currently underway at NIH and Yale University (see below).

“Parents will describe children with PANS as overcome by a ‘ferocious’ onset of obsessive thoughts, compulsive rituals and overwhelming fears,” said Susan Swedo, M.D., of the NIH’s National Institute of Mental Health (NIMH), who first characterized PANDAS two decades ago. “Clinicians should consider PANS when children or adolescents present with such acute-onset of OCD or eating restrictions in the absence of a clear link to strep.”

Swedo, James Leckman, M.D., of Yale University, and Noel Rose, M.D., Ph.D. of Johns Hopkins University, propose working criteria for PANS in February 2012 in the open source journal Pediatrics & Therapeutics.

“As the field moves toward agreement on this broadened syndrome, affected youth will be more likely to receive appropriate care, regardless of whether they are seen by a neurologist, pediatrician or child psychiatrist,” said NIMH Director Thomas R. Insel, M.D.

Differing causes sharing a “common presentation”

The PANS criteria grew out of a PANDAS workshop convened at NIH in July 2010, by the NIMH Pediatric and Developmental Neuroscience Branch, which Swedo heads. It brought together a broad range of researchers, clinicians and advocates. The participants considered all cases of acute-onset OCD, regardless of potential cause.

Clinicians reported that evaluations of more than 400 youth diagnosed with PANDAS confirmed that affected boys outnumbered girls 2:1, with psychiatric symptoms, always including OCD, usually beginning before 8 years.

Although debate continues about the fine points, the field is now of one mind on the core concept of “acute and dramatic” onset of a constellation of psychiatric symptoms. There is also broad agreement on the need for a “centralized registry” that will enable the research community to analyze evidence from studies that will eventually pinpoint causes and treatments. Such a registry is currently under development by members of the International Obsessive Compulsive Foundation (IOCDF).

Since a diagnosis of PANS implies no specific cause, clinicians will have to evaluate and treat each affected youth on a case-by-case basis.

“PANS will likely turn out to include a number of related disorders with different causes that share a common presentation,” explained Swedo.

The authors propose that a patient must meet 3 diagnostic criteria for a diagnosis of PANS:
1.Abrupt, dramatic onset of OCD or anorexia.
2.Concurrent presence of at least two additional neuropsychiatric symptoms with similarly severe and acute onset. These include: anxiety; mood swings and depression; aggression, irritability and oppositional behaviors; developmental regression; sudden deterioration in school performance or learning abilities; sensory and motor abnormalities; somatic signs and symptoms.
3.Symptoms are unexplainable by a known neurologic or medical disorder.

Among the wide range of accompanying symptoms, children may appear terror stricken or suffer extreme separation anxiety, shift from laughter to tears for no apparent reason, or regress to temper tantrums, “baby talk” or bedwetting. In some cases, their handwriting and other fine motor skills worsen dramatically. Leckman’s team at the Yale Child Study Center is in the process of developing assessment tools for diagnosing the syndrome.

PANDAS treatment study targets errant antibodies

Meanwhile, Swedo, Leckman, and Madeleine Cunningham of the University of Oklahoma, and colleagues, are collaborating on a new, multi-site placebo-controlled study, testing the effectiveness of intravenous immunoglobulin (IVIG) for reducing OCD symptoms in children with PANDAS.

Previous human and animal research suggested mechanisms by which strep-triggered antibodies mistakenly attack specific brain circuitry, resulting in obsessional thoughts and compulsive behaviors.

“Strep bacteria has evolved a kind of camouflage to evade detection by the immune system,” Swedo explained. “It does this by displaying molecules on its cell wall that look nearly identical to molecules found in different tissues of the body, including the brain. Eventually, the immune system gets wise to this ‘molecular mimicry,’ recognizes strep as foreign, and produces antibodies against it; but because of the similarities, the antibodies sometimes react not only with the strep, but also with the mimicked molecules in the human host. Such cross-reactive ‘anti-brain’ antibodies can cause OCD, tics, and the other neuropsychiatric symptoms of PANDAS.”

IVIG, a medication derived from normal antibodies, neutralizes such harmful antibodies, restoring normal immune function. It is used to treat other autoimmune illnesses and showed promise in a pilot study with PANDAS patients.

“We predict that IVIG will have striking benefits for OCD and other psychiatric symptoms, and will prove most effective for children who show high levels of anti-brain antibodies when they enter the study,” said Swedo.

Prospective study participants are first screened by phone by investigators at the NIH or the Yale Child Study Center. Those who meet eligibility requirements are then randomized to receive either active IVIG or a placebo procedure during a brief inpatient stay at the NIH Clinical Center. The researchers remain blind to which children received the active medication; after 6 weeks of placebo control, they give any children whose symptoms fail to improve the option to receive open-label active treatment.

In addition to assaying for antibodies that attack brain cells, the researchers use magnetic resonance imaging to see if the treatment reduces inflammation in an area of the brain known as the basal ganglia, which is thought to be the target of the errant antibodies. They also analyze levels of immune system chemical messengers (cytokines) in cerebrospinal fluid and blood – with an eye to identifying biomarkers of disease activity and potential predictors of treatment response.

The study was launched with support from the NIH Clinical Center’s Bench to Bedside program, which encourages such intramural-extramural collaborations in translational science.


Children with PANS and PANDAS sometimes experience sudden loss of fine motor skills.
Source: Susan Swedo, M.D., NIMH Pediatric and Developmental Neuroscience Branch

Reference:

Swedo, SE, Leckman JF, Rose, NR. From Research Subgroup to Clinical Syndrome: Modifying the PANDAS criteria to describe PANS (Pediatric Acute-onset Neuropsychiatric Syndrome). Feb 2012, Pediatrics & Therapeutics.

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The mission of the NIMH is to transform the understanding and treatment of mental illnesses through basic and clinical research, paving the way for prevention, recovery and cure. For more information, visit the NIMH website.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit the NIH website.

Linked Brain Centers Mature in Sync

Imaging Reveals Underlying Unity Between Brain Structure and Development

Long-term neuroimaging studies show for the first time that areas of the brain that are wired together structurally and functionally also tend to mature in tandem over the course of development. The finding adds a new dimension to a picture that is emerging of how structure, function, and development of the brain are intertwined ceus for mfts

Background

Studies of brain development have shown that growth across the brain is not steady and uniform; some areas mature more quickly than others. These studies to date have not, however, examined whether areas of the brain that are linked functionally also develop in a coordinated way. It’s a challenging question because the developmental changes in brain anatomy that can be detected by neuroimaging unfold very slowly. Also, tempos of anatomical change differ from person to person, so comparing brain dimensions in different individuals at the same age can be misleading. The only way to approach this question is to track patterns of growth in the same individuals over many years.

This Study

To address this question, Armin Raznahan and colleagues at NIMH took advantage of a dataset that is unique in the world, consisting of records of brain growth measured by magnetic resonance imaging (MRI) of individuals from childhood to young adulthood. They studied changes in thickness of the outer layer of the brain, the cortex. In order to look for correlated anatomical change in connected parts of the brain, these investigators used records of cortical thickness from 108 individuals from ages 9 to 22. They focused on a well-defined and documented brain circuit: the default mode network or DMN. The DMN, a network identified by functional brain imaging, consists of nodes, or centers, in the brain that are active when someone’s mind is at rest, but quiet when the mind is focused on a task. In addition to tracking growth in the DMN, the NIMH investigators also looked at patterns of growth on the right and left side of the brain. There are extensive neuronal connections between the right and left hemispheres of the brain. Activation tends to be symmetrical and simultaneous within analogous parts on either side of the brain.

Results showed that there was a marked correlation in the rates of cortical thickness change between different points within the DMN when compared with the average correlation among thousands of other points across the brain. A similar pattern was seen among points in a second “task positive” network that is active while someone is carrying out goal-directed tasks; rates of change in cortical thickness within this second network also showed a pattern of coordinated maturing. Parts of the cortex involved in the integration and processing of incoming information and responses—the association cortex—were most likely to show correlated anatomical change with broad areas of the cortex. Similar correlations in change were not seen among parts of the cortex involved primarily in sensory input.

Correlations in anatomical change were also apparent between analogous centers on the right and left side of the brain, paralleling the symmetry in activation of these areas. Finally, the investigators looked at an area of the cortex (the frontopolar cortex) for which previous work had shown differences in the rate of maturation between males and females. This study found the same difference between males and females in maturation rate in this area. In addition, there were differences between the sexes in the degree to which thickness change in this area showed coordination with that of other areas of the cortex.

The coloring in this MRI scan reflects the extent to which changes in various areas of the maturing cortex correlate with similar changes over time in the default mode network, a network in the brain that is active when a person is at rest. Red indicates the highest degree of correlation—blue is the lowest. (Colors indicate correlation with one “node” within the default mode network, indicated by a circle in the image.)

Source: Armin Raznahan, Child Psychiatry Branch, National Institute of Mental Health


Significance

Neuroscientists are increasingly viewing the brain in terms of the development and function of neural circuits. According to Dr. Raznahan, this approach represents a sea change compared to the earlier emphasis on studying individual brain areas. In addition to the work reported here, recent studies of gene expression (activity) patterns in the brain suggest that genes that have roles in laying down connections between functionally related areas are also especially active during development.

In a high percentage of cases of mental disorders, the first symptoms emerge during youth; this is one piece of evidence that mental illnesses are disorders of development. Research on the relationships between brain connectedness and structural maturation can help provide a basis for future studies of how disruptions in the laying down of neural circuits in the brain during development can shape the structure and function of the adult brain and set the stage for mental illness. The authors point out in their paper that disorders that disrupt functional connections might also alter structural brain development. Comparing how development unfolds in individuals with and without disorders of mental health can offer clues to causes and targets for therapies. Finally, the findings on sex differences reported here can lend insight into the types of behavior seen during adolescence, especially risk-taking.

Reference

Raznahan, A., Lerch, J.P., Lee, N., Greenstein, D., Wallace, G., Stockman, M., Clasen, L., Shaw, P., and Giedd, J. Patterns of coordinated anatomical change in human cortical development: a longitudinal neuroimaging study of maturational coupling. Neuron. 2011 Dec 8;72(5):873-84.

Computer-Based Treatment Eases Anxiety Symptoms in Children

Small Clinical Trial Supports Larger Scale Testing

A computer-based training method that teaches a person with anxiety to shift attention away from threatening images reduced symptoms of anxiety in a small clinical trial in children with the condition. The results of this first randomized clinical trial of the therapy in children with anxiety suggest that the approach warrants more extensive testing as a promising therapy.

Background

As many as a quarter of 13- to 18-year-olds have met the criteria for an anxiety disorder at some point. Currently available treatments—including cognitive behavioral therapy and medication—relieve symptoms of anxiety in about 70 percent of children treated. Most children with clinical anxiety do not receive treatment, partly because of difficulties in access to care, including distance and financial resources. Scientists are searching for additional approaches, including therapies that do not involve medication with its associated side effects counselor ceus

A treatment called attention bias modification (ABM) has emerged from the observation that people with anxiety unconsciously pay more attention than others to anything that seems threatening. One way of detecting such a bias is a dot probe test. In the test, people view a computer screen on which angry and neutral faces are flashed briefly, adjacent to each other. After the faces disappear, a test image of dots appears where either one or the other face was, and the person has to respond by pushing a button. People with anxiety consistently respond more quickly to dots that appear where the angry face was located.

ABM presents patients with an exercise similar to the dot probe test, but the dots always appear where the neutral face was, and thus consistently draw the attention of the participant to this non-threatening image. A recent meta-analyses of ABM in adults by some of the same investigators who carried out this work suggested its potential as a treatment.

This Study

Researchers at Tel Aviv University (TAU) in Israel carried out a clinical trial on ABM as an outcome of a three-year collaboration with scientists at the National Institute of Mental Health and the University of Maryland, College Park, Maryland. Yair Bar-Haim of TAU led the study, which appears in the American Journal of Psychiatry. The study enrolled 40 children, 8 to 14 years old, who had sought help for anxiety. For children receiving ABM, after faces appeared on a screen, two dots appeared on the screen; children had to determine whether the dots were side by side, or one above the other. In every case, dots appeared only where the neutral face had been. There were also two control groups: in the first, dots appeared equally frequently where angry and neutral faces appeared; in the second, the only faces that appeared throughout were neutral, so the dots always appeared in the location of a neutral face. The object of the second control group was to help confirm that any therapeutic effect was from the ABM training, and not from desensitizing the children to threatening faces. Children in the study were randomly assigned to receive treatment, or to be in one of two control groups. All children had four training sessions over 4 weeks, with 480 dot-probe trials per session.

Although the trial was small, there was a “reasonably robust” decrease in the severity of anxiety, according to the authors. Following ABM, both the number and severity of symptoms were reduced.

Significance

An important feature of ABM, says NIMH author Daniel Pine, is that it addresses the fundamental neurological function underlying anxiety: attention. Changes in attention happen very quickly—in milliseconds. “We know from neuroscience that if you want to change behaviors that happen very quickly, you have to practice. You can’t just tell someone how to drive, or throw a ball. You have to practice,” says Pine.

Longitudinal studies that follow children into adulthood suggest that most chronic mood and anxiety disorders in adults begin as high levels of anxiety in children. In fact, childhood anxiety is as important in predicting adult depression as it is for adult anxiety. The ability to influence attention biases early in development might provide a powerful means of prevention for both of these disorders later in life. The approach requires no medication and in practical terms, the computer-based nature of ABM lends itself to large-scale dissemination, in a medium children are comfortable with. Larger-scale trials will be able to provide more information on the efficacy of the treatment in children and how it works to reduce symptoms of anxiety.

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Reference

Eldar, S., Apter, A., Lotan, D., Perez-Edgar, K., Naim, R, Fox, N.A., Pine, D.S., and Bar-Haim, Y. American Journal of Psychiatry. 2012 Feb 1;169(2):213-30.