Stress in the city: Brain activity and biology behind mood disorders of urbanites

ScienceDaily (June 23, 2011) — Being born and raised in a major urban area is associated with greater lifetime risk for anxiety and mood disorders. Until now, the biology for these associations had not been described. A new international study, which involved Douglas Mental Health University Institute researcher Jens Pruessner, is the first to show that two distinct brain regions that regulate emotion and stress are affected by city living. These findings, published in Nature may lead to strategies that improve the quality of life for city dwellers.

"Previous findings have shown that the risk for anxiety disorders is 21 percent higher for people from the city, who also have a 39 percent increase for mood disorders," says co-author Jens Pruessner, a Douglas researcher. "In addition, the incidence for schizophrenia is almost doubled for individuals who are born and brought up in cities. These values are a cause for concern and determining the biology behind this is the first step to remedy the trend."

Distinct brain structures

Pruessner, with his colleagues from the Central Institute of Mental Health in Mannheim, looked at the brain activity of healthy volunteers from urban and rural areas. In a series of functional magnetic resonance experiments involving the Douglas' previously developed 'Montreal Imaging Stress Task',(MIST) protocol, they showed that city living was associated with greater stress responses in the amygdala, an area of the brain involved with emotional regulation and mood. In contrast, urban upbringing was found to be associated with activity in the cingulate cortex, a region involved in regulation of negative affect and stress.

"These findings suggest that different brain regions are sensitive to the experience of city living during different times across the lifespan," says Pruessner. "Future studies need to clarify the link between psychopathology and these affects in individuals with mental disorders.These findings contribute to our understanding of urban environmental risk for mental disorders and health in general. They further point to a new approach to interface social sciences, neurosciences and public policy to respond to the major health challenge of urbanization."

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Douglas Mental Health University Institute.

Journal Reference:

Florian Lederbogen, Peter Kirsch, Leila Haddad, Fabian Streit, Heike Tost, Philipp Schuch, Stefan Wüst, Jens C. Pruessner, Marcella Rietschel, Michael Deuschle, Andreas Meyer-Lindenberg. City living and urban upbringing affect neural social stress processing in humans. Nature, 2011; 474 (7352): 498 DOI: 10.1038/nature10190

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Fast ripples confirmed to be valuable biomarker of area responsible for seizure activity in children

ScienceDaily (July 30, 2011) — New research focusing on high-frequency oscillations, termed ripples and fast ripples, recorded by intracranial electroencephalography (EEG), may provide an important marker for the localization of the brain region responsible for seizure activity. According to the study now available in Epilepsia, a journal of the International League Against Epilepsy (ILAE), the resection of brain regions containing fast ripples, along with the visually-identified seizure-onset zone, may achieve a good seizure outcome in pediatric epilepsy.

High-frequency oscillations at 80-200 Hz are known as ripples and those above 200 Hz are considered fast ripples. Medical evidence suggests that fast ripples are a specific surrogate marker of the seizure generation zone. Studies in adults have suggested that resection of the brain region containing fast ripples was associated with good seizure outcome. However, these studies used a small number of electrode (EEG) contacts, with limited brain coverage, which may not be optimal for pediatric patients who often exhibit a more generalized epileptic network than adults.

Hiroshi Otsubo, MD, with The Hospital for Sick Children in Toronto, Canada and lead researcher of the current study explains, "In pediatric patients, extensive surgical resection are often used, but may overestimate the link between high-frequency oscillations and seizure outcome. Good surgical success may also be achieved by more limited surgeries that include both the brain region with high-frequency oscillations and the brain region that appears to initiate seizures, even when they are independent." To further explore this hypothesis, the research team evaluated the relationship of resection of brain regions containing high-frequency oscillations and the area of seizure onset in pediatric epilepsy patients.

Researchers retrospectively analyzed 28 pediatric patients with epilepsy who underwent intracranial EEG monitoring prior to focal resection surgery. Brain regions containing a high occurrence of high-frequency oscillations were determined, and spatial relationships between regions with fast ripples and seizure-onset zones were investigated. The team compared seizure outcome with the size of these regions, the surgical resection, and amount of the regions with fast ripples and areas of seizure onset within the resection area.

Results show that 2 years after surgery, 10 patients were completely seizure free and 18 continued to have some seizure activity. Complete resection of the brain regions exhibiting fast ripples was significantly associated with better seizure outcome. Improved seizure outcome was also observed with complete resection of brain regions with ripples; surprisingly, however, resection of the area of seizure onset did not correlate with seizure outcome. The size of surgical resection was not linked to seizure outcome.

Furthermore, the authors, Drs. Akiyama and Otsubo et al., noted that the visually- determined seizure onset zone partially overlapped with regions containing high-rate fast ripples. "The entire epileptic network, containing fast ripples, ripples and seizure onset zones, must be thoroughly analyzed to ensure complete resection of the area causing seizures with the smallest resection possible," advised Drs. Akiyama and Otsubo et al. "While our results are preliminary and further validation is necessary, the analysis of high frequency oscillations offers clinicians a new surgical approach that could potentially improve seizure outcome in children with epilepsy."

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Wiley-Blackwell, via EurekAlert!, a service of AAAS.

Journal Reference:

Tomoyuki Akiyama, Bláthnaid McCoy, Cristina Y. Go, Ayako Ochi, Irene M. Elliott, Mari Akiyama, Elizabeth J. Donner, Shelly K. Weiss, O. Carter Snead, James T. Rutka, James M. Drake, Hiroshi Otsubo. Focal resection of fast ripples on extraoperative intracranial EEG improves seizure outcome in pediatric epilepsy. Epilepsia, 2011; DOI: 10.1111/j.1528-1167.2011.03199.x

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New imaging technique captures brain activity in patients with chronic low back pain

ScienceDaily (July 27, 2011) — Research from Brigham and Women's Hospital (BWH) uses a new imaging technique, arterial spin labeling, to show the areas of the brain that are activated when patients with low back pain have a worsening of their usual, chronic pain.

This research is published in the August issue of the journal Anesthesiology.

"This study is a first step towards providing tools to objectively describe someone's chronic pain which is a subjective experience. We've found that when a patient has worsening of their usual pain, there are changes in the activity of the brain," said Ajay Wasan, MD, MSc, lead author of the paper and a researcher in the Pain Management Center at BWH. "These changes occur in the network of areas in the brain that process pain and mood."

Researchers compared 16 patients with chronic low back pain (CLBP) to 16 healthy subjects. Participants underwent three imaging sessions. The first was for a characterization and training session. During the second session, researchers used clinical maneuvers, such as pelvic tilting or straight leg raising , to temporarily exacerbate back pain. In the third session, heat was applied to the skin at an intensity that matched the pain levels during the second session. Patients rated their pain levels before and after the sessions and after each stimulation during the sessions.

During the last two sessions, researchers used the arterial spin labeling technique, which allows them to quantify the blood flow to specific regions of the brain over time. The amount of blood flow is indicative of neuron activity in that region of the brain. They found that there was increased activity in the brain of CLBP patients only when they experienced a worsening of their chronic pain and not during the heat pain session or in the healthy participants. Researchers also note that some of the areas of the brain that were activated when participants experienced a worsening of chronic pain have been shown to be associated with other types of pain found in other studies. However, researchers also observed activation of some areas, including the superior parietal lobule, which have been less frequently associated with pain in previous research.

"While this study begins to uncover some of the basic physiology of the brain as it processes pain, more studies are needed to help us understand how the brain function may change over the course of treatment of pain and to examine the brain mechanisms by which pain improves," Wasan said. "We are getting closer to describing, on an objective level, how the body and brain are reacting when a patient reports having more pain. We are hopeful that this could lead to an understanding of an individual patient's neurocircuitry and that knowledge could lead to therapies that would be tailored to the individual."

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Brigham and Women's Hospital.

Journal Reference:

Ajay D. Wasan, Marco L. Loggia, Li Q. Chen, Vitaly Napadow, Jian Kong, Randy L. Gollub. Neural Correlates of Chronic Low Back Pain Measured by Arterial Spin Labeling. Anesthesiology, 2011; 115 (2): 364 DOI: 10.1097/ALN.0b013e318220e880

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People at risk for panic buffered from stressor by high levels of physical activity

ScienceDaily (July 14, 2011) — Regular exercise may be a useful strategy for helping prevent the development of panic and related disorders, a new study suggests.

People with an intense fear of the nausea, racing heart, dizziness, stomachaches and shortness of breath that accompany panic -- known as "high anxiety sensitivity" -- reacted with less anxiety to a panic-inducing stressor if they had been engaging in high levels of physical activity, said researchers at Southern Methodist University in Dallas and the University of Vermont in Burlington.

"Anxiety sensitivity is an established risk factor for the development of panic and related disorders," said SMU psychologist Jasper Smits, lead author on the research. "This study suggests that this risk factor may be less influential among persons who routinely engage in high levels of physical activity."

Regular exercise as an alternative or complementary strategy to drugs and psychotherapy

There is already good evidence that exercise can be of help to people who suffer from depression and anxiety problems, say the researchers.

"We're not suggesting, 'Exercise instead of pharmacotherapy or psychotherapy,'" Smits said. "Exercise is a useful alternative, particularly for those without access to traditional treatments. Primary care physicians already prescribe exercise for general health, so exercise may have the advantage of helping reach more people in need of treatment for depression and anxiety."

Smits reported the findings in "The Interplay Between Physical Activity and Anxiety Sensitivity in Fearful Responding to Carbon Dioxide Challenge," an article that has published online and is in press with the scientific journal Psychosomatic Medicine.

Co-authors include SMU psychology researchers Candyce Tart and David Rosenfield, and University of Vermont psychologist Michael Zvolensky.

New study adds to earlier research finding exercise reduces anxiety

The study builds on findings of earlier research, outlined in "Exercise for Mood and Anxiety: Proven strategies for overcoming depression and enhancing well-being" (Oxford University Press, 2011) by psychologists Michael Otto and Jasper Smits. That research indicates exercise improves mood and reduces anxiety, working like "an antidepressant drug."

Also, a 2008 study by Smits, director of the SMU Anxiety Research & Treatment Program and associate professor in the SMU Psychology Department, and Otto, a professor in Boston University's Psychology Department, indicated that exercise can also reduce anxiety sensitivity. That research, combined with the new findings, indicates that exercise may be an effective strategy for the prevention and treatment of anxiety disorders.

"Exercise can be a powerful addition to the range of treatments for depression, anxiety and general stress," said Otto. "And when people exercise to feel good, they are also taking the exact steps they need to benefit their general health."

Those with high anxiety sensitivity have greater risk of an attack

Anxiety sensitivity is the extent to which individuals fear they will be harmed by anxiety-related bodily sensations such as a racing heart, dizziness and shortness of breath, say the authors.

Research shows that the higher a person's anxiety sensitivity, the greater their risk for developing panic attacks and related psychological disorders.

"For people who have high anxiety sensitivity, the symptoms of anxiety tend to signal threat," said Smits. "They worry, 'I'll have a panic attack,' 'I'll die,' 'I'll go crazy,' 'I'll lose control' or 'I'll make a fool of myself.' That's been widely studied as one of the risk factors for development of anxiety disorders, mostly panic. And it's a robust risk factor in that it's been replicated in several studies."

Physical activity + fear of panic sensations = less reactivity to panic-relevant stressor

For the latest study, the researchers measured anxiety reactivity to a panic-related stressor, namely the inhalation of carbon dioxide-enriched air.

Study participants were 145 adult volunteers who had no history of panic attacks. After completing questionnaires measuring their physical activity and anxiety sensitivity, the participants inhaled a mixture of room air enriched with carbon dioxide, a benign procedure that typically induces a number of bodily sensations, including nausea, racing heart, dizziness, stomachaches and shortness of breath.

After inhalation, participants indicated their level of anxiety in reaction to the sensations.

The results showed that anxiety reactivity to the stressor was dampened among individuals who have been regularly engaging in high levels of physical activity.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Southern Methodist University.

Journal Reference:

Jasper A.J. Smits, Candyce D. Tart, David Rosenfield and Michael J. Zvolensky. The Interplay Between Physical Activity and Anxiety Sensitivity in Fearful Responding to Carbon Dioxide Challenge. Psychosomatic Medicine, July 2011 vol. 73 no. 6 498-503 DOI: 10.1097/%u200BPSY.0b013e3182223b28

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Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here