PRESS-NEWS.org - Press Release Distribution
FREE PRESS RELEASES DISTRIBUTION

Study shows adaptive brain response to stress, and its absence in people with depression

A biological signal for resilience to stress

2021-06-09
(Press-News.org) A new study identifies a novel biomarker indicating resilience to chronic stress. This biomarker is largely absent in people suffering from major depressive disorder, and this absence is further associated with pessimism in daily life, the study finds.

Nature Communications published the research by scientists at Emory University.

The researchers used brain imaging to identify differences in the neurotransmitter glutamate within the medial prefrontal cortex before and after study participants underwent stressful tasks. They then followed the participants for four weeks, using a survey protocol to regularly assess how participants rated their expected and experienced outcomes for daily activities.

"To our knowledge, this is the first work to show that glutamate in the human medial prefrontal cortex shows an adaptive habituation to a new stressful experience if someone has recently experienced a lot of stress," says Michael Treadway, senior author of the study and professor in Emory's Department of Psychology and Department of Psychiatry and Behavioral Science. "Importantly, this habituation is significantly altered in patients with depression. We believe this may be one of the first biological signals of its kind to be identified in relation to stress and people who are clinically depressed."

"Learning more about how acute stress and chronic stress affect the brain may help in the identification of treatment targets for depression," adds Jessica Cooper, first author of the study and a post-doctoral fellow in Treadway's Translational Research in Affective Disorders Laboratory.

The lab focuses on understanding the molecular and circuit-level mechanisms of psychiatric symptoms related to mood disorders, anxiety and decision-making.

It's long been known that stress is a major risk factor for depression, one of the most common and debilitating of mental illnesses. "In many ways, depression is a stress-linked disorder," Treadway says. "It's estimated that 80 percent of first-time depressive episodes are preceded by significant, chronic life stress."

Around 16 to 20 percent of the U.S. population will meet the criteria for a major depressive disorder during their lifetimes. Experts are predicting rates of depression to climb even further in the wake of the ongoing COVID-19 pandemic. During the pandemic, about four in 10 adults in the United States have reported symptoms of anxiety or depressive disorder, up from one in 10 who reported them in 2019, according to the Kaiser Family Foundation.

"The pandemic has created more isolation for many people, while also increasing the amount of severe stressors and existential threats they experience," Treadway says. "That combination puts a lot of people at high risk for becoming depressed."

Although the link between stress and depression is clearly established, the mechanisms underlying this relationship are not. Experiments with rodents have shown an association between the response of glutamate -- the major excitatory neurotransmitter in the mammalian brain -- and stress. The role of glutamate in humans with depression, however, has been less clear.

The 88 participants in the current study included people without a mental health disorder and unmedicated patients diagnosed with a major depressive disorder. Participants were surveyed about perceived recent stress in their lives before they underwent experiments using a brain scanning technique known as magnetic resonance spectroscopy.

While in the scanner, participants were required to alternate between performing two tasks that served as acute stressors: Putting their hand up to the wrist in ice water and counting down from the number 2,043 by steps of 17 while someone evaluated their accuracy.

Brain scans before and after the acute stressor measured glutamate in the medial prefrontal cortex, an area of the brain involved with thinking about one's state and forming expectations. Previous research has also found that this brain area is involved in regulating adaptive responses to stress.

Participants submitted saliva samples while in the scanner, allowing the researchers to confirm that the tasks elicited a stress response by measuring the amount of the stress hormone cortisol in the sample.

In healthy individuals, the brain scans revealed that glutamate change in response to stress in the medial prefrontal cortex was predicted by individual levels of recent perceived stress. Healthy participants with lower levels of stress showed increased glutamate in response to acute stress, while healthy participants with higher levels of stress showed a reduced glutamate response to acute stress. This adaptive response was comparatively absent in the patients diagnosed with depression.

"The decrease in the glutamate response over time appears to be a signal, or a marker, of a healthy adaptation to stress," Treadway says. "And if the levels remain high that appears to be a signal for maladaptive responses to stress."

The initial result was strong for the adaptation in healthy participants, but was in a modest sample size, so the researchers decided to see if they could replicate it. "Not only did we get a replication, it was an unusually strong replication," Treadway says.

The experiment also included a group of healthy controls who underwent scanning before and after performing tasks. Rather than stressful tasks, however, the controls were asked to place a hand into warm water or to simply count out loud consecutively. Their glutamate levels were not associated with perceived stress and they did not show a salivary cortisol response.

To expand their findings, the researchers followed participants for four weeks after scanning. Every other day, the participants reported on their expected and experienced outcomes for activities in their daily lives. The results showed that glutamate changes that were higher than expected based on an individual's level of perceived stress predicted an increased pessimistic outlook -- a hallmark for depression.

"We were able to show how a neural response to stress is meaningfully related to what people experience in their daily lives," Cooper says. "We now have a large, rich data set that gives us a tangible lead to build upon as we further investigate how stress contributes to depression."

INFORMATION:

Emory co-authors of the study include former and current graduate students from the Treadway lab Victoria Lawlor, Shabnam Hossein and Andrew Teer; as well as current and former research assistants Makiah Nuutinen, Brittany DeVries, Daniel Cole, Chelsea Leonard and Emma Hahn. Additional authors include researchers from UCLA, the University of Arkansas, Princeton and McLean Hospital/Harvard Medical School.

The work was supported by the National Institutes of Mental Health.



ELSE PRESS RELEASES FROM THIS DATE:

Heart transplants: Age is no barrier to successful surgery

2021-06-09
A new study published in the Journal of the American Geriatrics Society suggests that survival rates after heart transplant surgery are similar in adults ages 18 to 69 and adults ages 70 and older. Researchers examined a large U.S. database of patients who were listed as candidates for surgery to replace their failing hearts with healthier donor hearts. The researchers found that: Only 1 in 50 people who are considered for heart transplant surgery and 1 in 50 people who receive a heart transplant are ages 70 or older. For older adults in the study, the likelihood of surviving one or five years after a heart transplant was about the same as for younger adults. Having a ...

A link between childhood stress and early molars

2021-06-09
Early in her career neuroscientist Allyson Mackey began thinking about molars. As a researcher who studies brain development, she wanted to know whether when these teeth arrived might indicate early maturation in children. "I've long been concerned that if kids grow up too fast, their brains will mature too fast and will lose plasticity at an earlier age. Then they'll go into school and have trouble learning at the same rate as their peers," says Mackey, an assistant professor in the Department of Psychology at Penn. "Of course, not every kid who experiences stress or [is] low income will show this pattern of accelerated development." What would help, she thought, was a scalable, objective way—a physical manifestation, ...

Better-fitting face masks greatly improve COVID-19 protection

Better-fitting face masks greatly improve COVID-19 protection
2021-06-09
Even the best face masks work only as well as their fit. And poorly fitting face masks greatly increase the risk of infection from airborne pathogens compared to custom-fitted masks, according to a new study by the University of Cincinnati. Researchers in UC's College of Engineering and Applied Science used computerized tomography or CT scans of three different-sized face masks attached to three different-sized dummy heads to measure the gaps between the face and the fabric. Then they calculated the leaks from these gaps to determine the infection risk.  They found that while N95 masks are effective barriers against airborne diseases like COVID-19, poorly ...

New adaptable nanoparticle platform enables enhanced delivery of gene therapies

New adaptable nanoparticle platform enables enhanced delivery of gene therapies
2021-06-09
Scientists have developed polypeptide-based materials that act as effective vectors for delivering gene therapies. The first-of-its-kind platform enables the vectors to be adapted to suit the specific gene therapy cargo. The work, led by researchers from RCSI University of Medicine and Health Sciences and funded by Science Foundation Ireland, is published in Biomaterials Science. A major challenge for gene therapies is preparing them in a way that can deliver the genetic information into the host cells. For the Covid-19 vaccines that use mRNA technology, the genetic information is delivered ...

Having trouble falling asleep predicts cognitive impairment in later life

2021-06-09
DARIEN, IL - A study of nearly 2,500 adults found that having trouble falling asleep, as compared to other patterns of insomnia, was the main insomnia symptom that predicted cognitive impairment 14 years later. Results show that having trouble falling asleep in 2002 was associated with cognitive impairment in 2016. Specifically, more frequent trouble falling asleep predicted poorer episodic memory, executive function, language, processing speed, and visuospatial performance. Further analysis found that associations between sleep initiation and later cognition were partially explained by both depressive symptoms and vascular ...

Persistent insomnia symptoms since childhood associated with mood, anxiety disorders

2021-06-09
DARIEN, IL - A 15-year longitudinal study shows that childhood insomnia symptoms that persist into adulthood are strong determinants of mood and anxiety disorders in young adults. Results show that insomnia symptoms persisting from childhood through adolescence and into adulthood were associated with a 2.8-fold increased risk of internalizing disorders. Insomnia symptoms that newly developed over the course of the study were associated with a 1.9-fold increased risk of internalizing disorders. No increased risk of internalizing disorders was found for those children in whom insomnia symptoms remitted during the study period. "We found that about ...

Measuring sound diversity of quietness

Measuring sound diversity of quietness
2021-06-09
MELVILLE, N.Y., June 9, 2021 -- The world is filled with myriad sounds that can overwhelm a person with relentless acoustics. Noise is so prevalent in everyday life that the concept and achievement of comfortable quiet is hard to define. During the 180th Meeting of the Acoustical Society of America, which will be held virtually June 8-10, Aggelos Tsaligopoulos, from the University of the Aegean, will describe how quiet could be measured in the hopes of better understanding its impact on people. The session, "Towards a new understanding of the concept of quietness," will take place Wednesday, ...

Australian researchers create quantum microscope that can see the impossible

Australian researchers create quantum microscope that can see the impossible
2021-06-09
In a major scientific leap, University of Queensland researchers have created a quantum microscope that can reveal biological structures that would otherwise be impossible to see. This paves the way for applications in biotechnology, and could extend far beyond this into areas ranging from navigation to medical imaging. The microscope is powered by the science of quantum entanglement, an effect Einstein described as "spooky interactions at a distance". Professor Warwick Bowen, from UQ's Quantum Optics Lab and the ARC Centre of Excellence for Engineered Quantum Systems (EQUS), said it was the first entanglement-based sensor with performance beyond the best possible existing technology. "This breakthrough will spark all sorts of new technologies - from better navigation ...

Assessing feasibility concerns in climate mitigation scenarios

2021-06-09
While the IPCC is in the midst of the drafting cycle of the Sixth Assessment Report, whose publication will start in the second half of 2021 - one of the most relevant events for the global climate change community, there is an ongoing debate on how to assess the feasibility of ambitious climate mitigation scenarios developed through integrated assessment models and to what extent they are actually achievable in the real world. In their new study published in Environmental Research Letters, researchers from the RFF-CMCC European Institute on Economics and the Environment (EIEE) and IIASA developed a systematic ...

Are social, behavioral risk factors associated with mortality among us veterans with COVID-19?

2021-06-09
What The Study Did: An observational study of more than 27,000 veterans who received a positive test result for COVID-19 reports that risk factors such as housing problems, financial hardship, alcohol use, tobacco use and substance use weren't associated with higher mortality. Authors: J. Daniel Kelly, M.D., M.P.H., of the University of California, San Francisco, is the corresponding author. To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/ (doi:10.1001/jamanetworkopen.2021.13031) Editor's Note: The article includes funding/support disclosures. Please ...

LAST 30 PRESS RELEASES:

Blackologists and the Promise of Inclusive Sustainability

Robot-assisted surgery: Putting the reality in virtual reality

Novel interactions between proteins that help in recovering from brain injury

Common antibiotic found useful in accelerating recovery in tuberculosis patients

The 'Mozart effect' shown to reduce epileptic brain activity, new research reveals

Study examines heart and kidney outcomes of adults with nephrotic syndrome

Study examines symptoms before and after kidney transplantation

New research adds a wrinkle to our understanding of the origins of matter in the Milky Way

Stronger together: how protein filaments interact

New study uncovers details behind the body's response to stress

Carcinogen-exposed cells provide clues in fighting treatment-resistant cancers

Memory helps us evaluate situations on the fly, not just recall the past

Animals' ability to adapt their habitats key to survival amid climate change

Undiagnosed and untreated disease identified in rural South Africa

Study reveals new therapeutic target for C. difficile infection

New artificial heart shows promising results in 'auto-mode' -- initial clinical experience reported in ASAIO Journal

Picky neurons

Does cannabis affect brain development in young people with ADHD? Too soon to tell, reports Harvard Review of Psychiatry

Researchers find optimal way to pay off student loans

Use rewards effectively to boost creativity

Researchers find losartan is not effective in reducing hospitalization from mild COVID-19

Scientists detect signatures of life remotely

Team describes science-based hiccups intervention

Princeton-led team discovers unexpected quantum behavior in kagome lattice

Overcoming a newly recognized form of resistance to modern prostate cancer drugs

Will reduction in tau protein protect against Parkinson's and Lewy body dementias?

The end of Darwin's nightmare at Lake Victoria?

Study: Men doing more family caregiving could lower their risk of suicide

Researchers dig deeper into how cells transport their waste for recycling

Organic farming could feed Europe by 2050

[Press-News.org] Study shows adaptive brain response to stress, and its absence in people with depression
A biological signal for resilience to stress