Tag: anxiety

The Sound of Traffic Increases Stress and Anxiety

People experienced less stress and anxiety while listening to nature soundscapes, but the addition of road traffic noise increased their stress and anxiety

Photo by Lucas Davies on Unsplash

Manmade sounds such vehicle traffic can mask the positive impact of nature soundscapes on people’s stress and anxiety, according to a new study published November 27, 2024, in the open-access journal PLOS ONE by Paul Lintott of the University of the West of England, U.K., and Lia Gilmour of the Bat Conservation Trust, U.K.

Existing research shows that natural sounds, like birdsong, can lower blood pressure, heart, and respiratory rates, as well as self-reported stress and anxiety. Conversely, anthropogenic soundscapes, like traffic or aircraft noise, are hypothesized to have negative effects on human health and wellbeing in a variety of ways.

In the new study, 68 student volunteers listened to three 3-minute soundscapes: a nature soundscape recorded at sunrise in West Sussex, U.K., the same soundscape combined with 20 mile per hour road traffic sounds, and the same soundscape with 40 mile per hour traffic sounds. General mood and anxiety were assessed before and after the soundscapes using self-reported scales.

The study found that listening to a natural soundscape reduced self-reported stress and anxiety levels, and also enhanced mood recovery after a stressor. However, the benefits of improved mood associated with the natural soundscape was limited when traffic sounds were included. The natural soundscape alone was associated with the lowest levels of stress and anxiety, with the highest levels reported after the soundscape that included 40 mile per hour traffic.

The authors conclude that reducing traffic speed in urban areas might influence human health and wellbeing not only through its safety impacts, but also through its effect on natural soundscapes.

The authors add: “Our study shows that listening to natural soundscapes can reduce stress and anxiety, and that anthropogenic sounds such as traffic noise can mask potential positive impacts. Reducing traffic speeds in cities is therefore an important step towards more people experiencing the positive effects of nature on their health and wellbeing.”

Provided by PLOS

Research Reveals a New Target to Treat Anxiety

A healthy neuron. Credit: NIH

Scientists at Université de Montréal and its affiliated Montreal Clinical Research Institute (IRCM) have uncovered unique roles for a protein complex in the structural organisation and function of brain cell connectivity, as well as in specific cognitive behaviours.

The work by a team led by Hideto Takahashi, director of the IRCM’s synapse development and plasticity research unit, in collaboration with Steven Connor’s team at York University and Masanori Tachikawa’s team at Japan’s Tokushima University is published in The EMBO Journal.

Although defects in synapse organisation are linked to many neuropsychiatric conditions, the mechanisms responsible for this organisation are poorly understood. The new study’s findings could provide valuable therapeutic insights, the researchers believe.

Two goals are important to bear in mind with this research, said Takahashi, an associate research medical professor in molecular biology and neuroscience at UdeM.

“One is to uncover novel molecular mechanisms for brain cell communication,” he said. “The other is to develop a new unique animal model of anxiety disorders displaying panic disorder- and agoraphobia-like behaviours, which helps us develop new therapeutic strategies.”

Understanding the mechanisms

Synapses are essential for neuronal signal transmission and brain functions. Defects in excitatory synapses, which activate signal transmission to target neurons, and those in synaptic molecules predispose to many mental illnesses.

Takahashi’s team has previously discovered a new protein complex within the synaptic junction, called TrkC-PTPσ, which is only found in excitatory synapses. The genes coding for TrkC (NTRK3) and PTPσ (PTPRS) are associated with anxiety disorders and autism, respectively. However, the mechanisms by which this complex regulates synapse development and contributes to cognitive functions are unknown.

The work carried out in the new study by first author Husam Khaled, a doctoral student in Takahashi’s laboratory, showed that the TrkC-PTPσ complex regulates the structural and functional maturation of excitatory synapses by regulating the phosphorylation, a biochemical protein modification, of many synaptic proteins, while disruption of this complex causes specific behavioural defects in mice.

Building blocks of the brain

Neurons are the building blocks of the brain and the nervous system that are responsible for sending and receiving signals that control the brain and body functions. Neighbouring neurons communicate through synapses, which act like bridges that allow the passage of signals between them.

This process is essential for proper brain functions such as learning, memory and cognition. Defects in synapses or their components can disrupt communication between neurons, and lead to various brain disorders.

By generating mice with specific genetic mutations that disrupt the TrkC-PTPσ complex, Takahashi’s team uncovered the unique functions of this complex. They demonstrated that this complex regulates the phosphorylation of many proteins involved in synapse structure and organisation.

High-resolution imaging of the mutant mice brains revealed abnormal synapse organisation, and further study of their signaling properties showed an increase in inactive synapses with defects in signal transmission. Observing the behaviour of the mutant mice, the scientists saw that they exhibited elevated levels of anxiety, especially enhanced avoidance in unfamiliar conditions, and impaired social behaviours.

Source: University of Montreal

Managing your Mental Health at your Own Tempo

Photo by Sammy Williams on Unsplash

World Mental Health Day, celebrated internationally on 10 October, is not just another commemorative day, but in fact, a time to truly reflect on the need to break the stigma associated with seeking mental health support.

Today, many may acknowledge that mental health issues are common and can adversely affect a significant portion of the population. “In fact, according to the fourth annual Mental State of the World Report 2023, published in March 2024 by Sapien Labs, Brazil, South Africa and the United Kingdom all show the greatest proportion of respondents who are distressed or struggling with their mental health, which indicates that there is still a dire need for more open conversations about mental health in families, workplaces and communities,” says Madelein O’Connell, Executive: Marketing, Sales and Corporate Relations at Bestmed Medical Scheme.

“We already know that our mental wellbeing can affect emotions, physical health, relationships and overall quality of life,” adds O’Connell. “Beyond this, neglecting your mental health can also lead to burnout, anxiety, and an array of serious health conditions. However, prioritising your mental health can be daunting, with so many not knowing where to start. It’s important to remember that it starts with, and is built on, small, consistent steps, which can make a significant difference.”

From a medical scheme perspective, there is often a range of mental health services covered as supplementary benefits by the medical scheme, such as access to psychologists, psychiatrists, counsellors, and support for conditions like anxiety, depression, and trauma. It’s important for members to understand what their medical scheme provides.

“At Bestmed, we offer a free Tempo wellness programme for our members, which can be accessed via the Bestmed App or online Member portal. As part of the Tempo wellness programme, members have access to free Tempo Wellness Webinars, hosted by mental healthcare experts, who discuss and give advice on various relevant topics,” says O’Connell. 

“We really want to support the integration of mental, nutritional, and physical health in overall wellbeing for our members, as we recognise that mental health covers a wide array of aspects. In fact, the World Health Organisation (WHO), defines mental health as ‘a state of mental well-being that enables people to cope with the stresses of life, realise their abilities, learn well and work well, and contribute to their community’, so giving people the support and skills to navigate their life is vital, particularly those more vulnerable to mental health challenges, such as adolescents, the elderly, or individuals dealing with long-term physical illness.”

Madelein O’Connell concludes, “of course, we also recognise that limited mental health service availability, a shortage of mental health professionals and financial constraints can impact a person’s ability to find the right support they need, when they need it. However, there are also some incredible mental health support organisations, locally, that can assist. LifeLine and The South African Depression and Anxiety Group (SADAG), for example, are confidential, free, and offer a starting point for anyone in need.”

Do Videogames Made to Improve Children’s Mental Health Work?

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In a review of 27 different studies, a Johns Hopkins Children’s Center team concludes that some video games created as mental health interventions can be helpful – if modest – tools in improving the mental well-being of children and teens with depression and attention-deficit/hyperactivity disorder (ADHD). They did not significantly help with anxiety, however.

A report on the review of studies from peer-reviewed journals between 2011 and March 20, 2024, was published in JAMA Pediatrics.

An estimated 20% of children and teenagers ages three to 17 in the US have a mental, emotional, developmental or behavioural disorder.

“We found literature that suggests that even doubling the number of paediatric mental health providers still wouldn’t meet the need,” says Barry Bryant, MD, a resident in the Department of Psychiatry and Behavioral Sciences in the Johns Hopkins University School of Medicine and first author of the new study.

In a bid to determine if so-called “gamified digital mental health interventions,” or video games designed to treat mental health conditions, benefited those with anxiety, depression and ADHD, the research team analysed their use in randomised clinical trials for children and adolescents.

Bryant and child and adolescent psychologist Joseph McGuire, PhD, identified 27 such trials from the US and around the world. The studies overall included 2911 participants with about half being boys and half being girls, ages six to 17 years old.

The digital mental health interventions varied in content, but were all created with the intent of treating ADHD, depression and anxiety. For example, for ADHD, some of the games involved racing or splitting attention, which required the user to pay attention to more than one activity to be successful in gameplay. For depression and anxiety, some of the interventions taught psychotherapy-oriented concepts in a game format. All games were conducted on technology platforms, such as computers, tablets, video game consoles and smartphones. The video games are available to users in a variety of ways. Some are available online, while others required access through specific research teams involved in the studies.

The research team’s analysis found that video games designed for patients with ADHD and depression provided a modest reduction (both with an effect size of .28) in symptoms related to ADHD and depression, such as improved ability to sustain attention and decreased sadness, based on participant and family feedback from the studies. (An effect size of .28 is consistent with a smaller effect size, where as in-person interventions often produce moderate [.50] to large [.80] effects.)  By contrast, video games designed for anxiety did not show meaningful benefits (effect size of .07) for reducing anxiety symptoms for participants, based on participant and family feedback.

Researchers also examined factors that led to improved benefit from digital mental health interventions. Specific factors related to video game delivery (i.e., interventions on computers and those with preset time limits) and participants (i.e., studies that involved more boys) were found to positively influence therapeutic effects. Researchers say these findings suggest potential ways to improve upon the current modest symptom benefit.

“While the benefits are still modest, our research shows that we have some novel tools to help improve children’s mental health – particularly for ADHD and depression – that can be relatively accessible to families,” says Joseph McGuire, Ph.D., an author of the study and an associate professor of psychiatry and behavioural sciences in the school of medicine. “So if you are a paediatrician and you’re having trouble getting your paediatric patient into individual mental health care, there could be some gamified mental health interventions that could be nice first steps for children while waiting to start individual therapy.”

The team cautioned that their review did not indicate why certain video game interventions performed better than others. They also note that some of the trials included in the study used reported outcome measures, and the studies did not uniformly examine the same factors which could have influenced the effects of the treatment. Some of the video games included in the studies are not easily accessible to play.

The researchers also noted that while video game addiction and the amount of screen time can be concerns, those children who played the games studied in a structured, time-limited format tended to do best.

Source: Johns Hopkins Medicine

Mental Health and Diabetes Complications are Strongly Interlinked, New Study Finds

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Myocardial infarction, stroke, neuropathy: when a person has any of these chronic diabetes complications, they are more likely to have a mental health disorder, and vice versa, according to a University of Michigan-led study. 

“We wanted to see if chronic diabetes complications led to mental health disorders or if mental health disorders led to those diabetes complications – but we found that both relationships are true,” said Brian Callaghan, MD, MS, senior author of the study published in Diabetes Care

“The findings highlight a need for clinicians to actively screen for mental health disorders in patients with diabetes in addition to screening for chronic complications, which is the recommended standard of care in diabetes.”

Three-times greater risk

The research team, led by Michigan Medicine and the Department of Biostatistics at the U-M School of Public Health, examined insurance claims data from over 500 000 individuals with type 1 or type 2 diabetes and 350 000 people without diabetes. 

The results reveal that people with chronic diabetes complications had up to a three-times greater risk of having a mental health condition, such as anxiety or depression. This effect increased as adults got older. 

Those with mental health disorders were up to 2.5 times more likely to experience sustained diabetes complications. 

In adults younger than 60 years old, having type 1 diabetes was more associated with chronic complications. People with the more common type 2 diabetes were more likely to experience mental health difficulties. 

A possible reason for this bi-directional relationship, researchers say, may be that having a diabetes complication or mental health condition has direct effects on developing the other complication.

“For instance, a stroke causes detrimental effects on the brain, which may directly lead to depression,” Callaghan said. 

“And having a mental health condition and diabetes may affect a person’s self-management of their condition – like poor glycaemic control or not taking medications – which, in turn, may increase their risk of diabetes complications.”

Common risk factors

The relationship may also be less direct. Diabetes complications and mental health conditions share common risk factors; obesity, issues with glycaemic control and social determinants of health can all increase the likelihood of developing both comorbidities. 

“Most likely, a combination of direct and indirect effects and shared risk factors drive the association we are seeing,” said first author Maya Watanabe, MS, a biostatistician at the Harvard T.H. Chan School of Public Health and former graduate student research assistant at U-M.  

“Diabetes care providers may be able to simultaneously prevent the risk of multiple complications by providing interventions to treat these shared risk factors.” 

Source: University of Michigan

Two Reasons I’m Sceptical About Psychedelic Science

Photo by Marek Piwnicki

Michiel van Elk, Leiden University

Since I was young, I have been intrigued by altered states of consciousness, such as out-of-body experiences, paranormal phenomena and religious visions. I studied psychology and neuroscience to gain a better understanding of how these experiences come about. And in my scientific career, I have focused on the question of why some people are more prone to having these experiences than others.

Naturally, when I came across psychedelic science a couple of years ago, this field also sparked my academic interest. Here was an opportunity to study people who had a psychedelic experience and who claimed to have had a glimpse of ultimate reality. I started to research psychedelic experiences at Leiden University and founded the PRSM lab – a group of scientists from different academic backgrounds who study psychedelic, religious, spiritual and mystical experiences.

Initially, I was enthusiastic about the mind-transforming potential of psychedelics. These substances, when administered correctly, appear to be capable of enhancing people’s mental and physical wellbeing. They also increase feelings of connectedness to and concern for the environment.

Psychedelic therapy appeared to offer great potential for treating a wide variety of disorders, including depression, anxiety, addiction and post-traumatic stress disorder. This enthusiasm about the potentially transformative effects of psychedelics was reflected in positive media attention on this topic over the past few years. Michael Pollan, an American author and journalist, has brought psychedelics to an audience of millions with his book and Netflix documentary.

However, my initial optimism about psychedelics and their potential has changed into scepticism about the science behind much of the media hype. This is due to a closer scrutiny of the empirical evidence. Yes, at face value it seems as if psychedelic therapy can cure mental disease. But on closer inspection, the story is not that straightforward.

The main reason? The empirical evidence for the efficacy of and the working mechanisms underlying psychedelic therapy is far from clear.

Two issues

I wrote a critical review paper with my colleague Eiko Fried in which we listed the problems with the current clinical trials on psychedelic therapy. The main concern is called the “breaking blind problem”. In psychedelic studies, patients easily figure out if they have been randomly assigned to the psychedelic or the placebo group, simply because of the profound mind-altering effects of psychedelic substances.

This breaking-of-the-blind can actually result in placebo effect in patients in the psychedelic group: they finally get the treatment they’d been hoping for and they start feeling better. But it can also result in frustration and disappointment in patients assigned to the control group. They were hoping to get a miracle cure but now find out they will have to spend six hours on a placebo pill with their therapist.

As a consequence, any difference in therapeutic outcomes between the psychedelic and the placebo group is largely driven by these placebo and nocebo effects. (A nocebo effect is when a harmless treatment causes side-effects or worsening of symptoms because the person believes they may occur or expects them to occur.)

Knowing who received what also affects the therapists, who may be motivated to get more out of the therapy session if their patient got the “real deal”. And this problem is impossible to control for in so-called randomised controlled trials – still the gold standard in evaluating the effectiveness of drugs and treatments.

Also, non-clinical research on psychedelics faces problems. You may recall the graphic of a brain on psilocybin compared to one on a placebo (see below). Psilocybin increases the connections between different brain areas, which is represented in a colourful array of connecting lines.

This has become known as the “entropic brain hypothesis”. Psychedelics make your brain more flexible such that it returns to a child-like state of openness, novelty and surprise. This mechanism in turn has been hypothesised to underlie psychedelic therapy’s efficacy: by “liberating your brain” psychedelics can change entrenched and maladaptive patterns and behaviour. However, it turns out the picture is much more complicated than that.

Psychedelics constrict the blood vessels in your body and brain and this causes problems in the measurement of brain signals with MRI machines.

The graphic of the entropic brain may simply reflect the fact that the blood flow in the brain is dramatically altered under psilocybin. Also, it is far from clear what entropy exactly means – let alone how it can be measured in the brain.

A recent psilocybin study, which is yet to be peer-reviewed, found that only four out of 12 entropy measures could be replicated, casting further doubt on how applicable this mechanism of action is.

Although the story about psychedelics freeing your mind is compelling, it does not yet square well with the available empirical evidence.

These are just two examples that illustrate why it is important to be really cautious when you evaluate empirical studies in psychedelic science. Don’t trust findings at face value, but ask yourself the question: is the story too good or too simple to be true?

Personally, I have developed a healthy dose of scepticism when it comes to psychedelic science. I am still intrigued by psychedelics’ potential. They offer great tools for studying changes in consciousness. However, it is too early to conclude anything definite about their working mechanisms or their therapeutic potential. For this, we need more research. And I’m excited to contribute to that endeavour.

Michiel van Elk, Associate Professor, Cognitive Psychology, Leiden University

This article is republished from The Conversation under a Creative Commons license.

Read the original article.

High-fat Diets can Interfere with Serotonin Pathways, Fuelling Anxiety

Photo by Jonathan Borba

New research from CU Boulder shows that turning to junk food when we’re stressed out may backfire. The study found that in animals, a high-fat diet disrupts resident gut bacteria, alters behaviour and, through a complex pathway connecting the gut to the brain, influences brain chemicals in ways that fuel anxiety.

“Everyone knows that these are not healthy foods, but we tend to think about them strictly in terms of a little weight gain,” said lead author Christopher Lowry, a professor of integrative physiology at CU Boulder. “If you understand that they also impact your brain in a way that can promote anxiety, that makes the stakes even higher.”

For the study, published in the journal Biological Research in May, Lowry worked with first author Sylvana Rendeiro de Noronha, a doctoral student at the Federal University of Ouro Preto in Brazil.

In a previous study, the team found that rats fed a high-fat diet consisting primarily of saturated fat showed increases in neuroinflammation and anxiety-like behaviour.

While evidence is mixed, some human studies have also shown that replacing a high-fat, high-sugar, ultra-processed diet with a healthier one can reduce depression and anxiety.

The dark side of serotonin

To better understand what may be driving the fat-anxiety connection, Lowry’s team divided male adolescent rats into two groups: Half got a standard diet of about 11% fat for nine weeks; the others got a high-fat diet of 45% fat, consisting mostly of saturated fat from animal products.

The typical American diet is about 36% fat, according to the Centers for Disease Control and Prevention.

Throughout the study, the researchers collected faecal samples and assessed the animals’ gut microbiome. After nine weeks, the animals underwent behavioural tests.

When compared to the control group, the group eating a high-fat diet, not surprisingly, gained weight. But the animals also showed significantly less diversity of gut bacteria. Generally speaking, more bacterial diversity is associated with better health, Lowry explained. They also hosted far more of a category of bacteria called Firmicutes and less of a category called Bacteroidetes. A higher Firmicutes to Bacteroidetes ratio has been associated with the typical industrialised diet and with obesity.

The high-fat diet group also showed higher expression of three genes (tph2, htr1a, and slc6a4) involved in production and signalling of the neurotransmitter serotonin – particularly in a region of the brainstem known as the dorsal raphe nucleus cDRD, which is associated with stress and anxiety.

While serotonin is often billed as a “feel-good brain chemical,” Lowry notes that certain subsets of serotonin neurons can, when activated, prompt anxiety-like responses in animals. Notably, heightened expression of tph2, or tryptophan hydroxylase, in the cDRD has been associated with mood disorders and suicide risk in humans.

“To think that just a high-fat diet could alter expression of these genes in the brain is extraordinary,” said Lowry. “The high-fat group essentially had the molecular signature of a high anxiety state in their brain.”

A primal gut-brain connection

Just how a disrupted gut can change chemicals in the brain remains unclear. But Lowry suspects that an unhealthy microbiome compromises the gut lining, enabling bacteria to slip into the body’s circulation and communicate with the brain via the vagus nerve, a pathway from the gastrointestinal tract to the brain.

“If you think about human evolution, it makes sense,” Lowry said.  “We are hard-wired to really notice things that make us sick so we can avoid those things in the future.”

Lowry stresses that not all fats are bad, and that healthy fats like those found in fish, olive oil, nuts and seeds can be anti-inflammatory and good for the brain.

But his research in animals suggests that exposure to an ultra-high-fat diet consisting of predominantly saturated fats, particularly at a young age, could both boost anxiety in the short-term and prime the brain to be more prone to it in the future.

His advice: Eat as many different kinds of fruits and vegetables as possible, add fermented foods to your diet to support a healthy microbiome and lay off the pizza and fries. Also, if you do have a hamburger, add a slice of avocado. Research shows that good fat can counteract some of the bad.

Rodrigo Cunha de Menezes, professor of physiology at Federal University of Ouro Preto in Brazil, is co- senior author on this paper.

Source: University of Colorado Boulder

Robust Analysis Challenges the Link Between Cancer and Anxiety and Depression

Photo by Karolina Grabowska on Pexels

Depression and anxiety are thought to increase a person’s risk of developing cancer, but research results have been inconclusive. In an analysis of multiple studies from the Netherlands, the UK, Norway, and Canada, investigators found that depression and anxiety are not linked to higher risks for most types of cancer among this population. The analysis is published in the journal CANCER.

Experts have suspected that depression and anxiety may increase cancer risk by affecting a person’s health-related behaviours or by having biological effects on the body that support cancer development. Some research has supported an association between depression, anxiety, and cancer incidence, while other investigations have found no or negligible associations.

To provide additional insights, Lonneke A. van Tuijl, PhD, of the University Medical Center Groningen, and her colleagues examined data from the international Psychosocial Factors and Cancer Incidence consortium, which includes information from 18 prospective study groups with more than 300 000 adults from the Netherlands, the United Kingdom, Norway, and Canada.

The team found no associations between depression or anxiety and overall, breast, prostate, colorectal, and alcohol-related cancers during a follow-up of up to 26 years. The presence of depression or anxiety was linked with a 6% higher risk of developing lung cancer and smoking-related cancers, but this risk was substantially reduced after adjusting for other cancer-related risk factors including smoking, alcohol use, and body mass index. Therefore, this analysis supports the importance of addressing tobacco smoking and other unhealthy behaviours including those that may develop as a result of anxiety or depression.

“Our results may come as a relief to many patients with cancer who believe their diagnosis is attributed to previous anxiety or depression,” said Dr van Tuijl. “However, further research is needed to understand exactly how depression, anxiety, health behaviours, and lung cancer are related.”

Source: Wiley

SA Retirement Home Study Reveals the Mental Health Benefits for Residents Interacting with Children

A small South African study published in the open-access journal PLOS ONE suggests that programmes promoting interaction between retirement home residents and children may provide quality of life improvements and could help manage residents’ anxiety and depression.

Among retirement home residents, previous research has shown that common mental health conditions often go undetected and untreated. These conditions, which include anxiety and depression, are typically treated with a combination of drugs and non-pharmacological interventions.

One intervention is the Eden Alternative, which identifies loneliness, helplessness and boredom as key challenges to overcome provide a higher quality of life. Evidence suggests that programmes that enable older adults to regularly interact with children may improve mental health, but these have mostly been done outside of retirement homes and few have looked at such programmes in South Africa.

To deepen the understanding of potential benefits of intergenerational interactions, Elizabeth Jane Earl and Debbie Marais of Stellenbosch University, South Africa, conducted a study at a retirement home in South Africa. Residents were able to regularly interact with children who attend an onsite preschool. Activities include playing games, doing puzzles, reading, or singing with the children.

Ten female residents were recruited and invited to complete a questionnaire evaluating their anxiety and depression levels, as well as asking them to describe their experiences with the children. Four of the participants were screened as possible having anxiety, depression, or both. The participants all took part in the same interactions, though to varying degrees of participation.

Generally, the participants reported positive experiences with the children. Analysing their responses, the researchers found that the interactions fostered a sense of purpose and belonging, fond reminiscences of their own childhood and a positive influence on mood and emotions. Recollections of childhood also sparked a sense of playfulness and positive self-evaluation. They noted that the participants differed in their preconceptions of children, which might have affected their experiences.

The authors wrote that, “Interactions with children promote a sense of belonging and purpose, evoke reminiscence, and positively influence the mental well-being of older persons.”

Based on their findings, Earl and Marais concluded that intergenerational interaction programmes may help manage the mental health conditions that are common for retirement home residents. They suggest that trained staff facilitate the interaction, preparing the children and residents, and should be voluntary, which helps preserve the residents’ agency. Running the interaction as a regular programme should help build bonds and give the residents something to look forward to. Additionally, there should be an educational aspect for the children, giving the residents a sense of purpose.

Looking to the future, they wrote that larger studies would be able to better outline the benefits of such programmes.

Brain Transmission Speeds Increase Until Middle Age

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It has been believed speed of information transmitted among regions of the brain stabilised during early adolescence. A study in Nature Neuroscience has instead found that transmission speeds continue to increase into early adulthood, which may explain the emergence of mental health problems over this period. In fact, transmission speeds increase until around age 40, reaching a speed twice that of a 4-year old child.

As mental health problems such as anxiety, depression and bipolar disorders can emerge in late adolescence and early adulthood, a better understanding of brain development may lead to new treatments.

“A fundamental understanding of the developmental trajectory of brain circuitry may help identify sensitive periods of development when doctors could offer therapies to their patients,” says senior author Dora Hermes, PhD, a biomedical engineer at Mayo Clinic.

Called the human connectome, the structural system of neural pathways in the brain or nervous system develops as people age. But how structural changes affect the speed of neuronal signalling has not been well described.

“Just as transit time for a truck would depend on the structure of the road, so does the transmission speed of signals among brain areas depend on the structure of neural pathways,” Dr Hermes explains. “The human connectome matures during development and aging, and can be affected by disease. All these processes may affect the speed of information flow in the brain.” In the study, Dr Hermes and colleagues stimulated pairs of electrodes with a brief electrical pulse to measure the time it took signals to travel among brain regions in 74 research participants between the ages of 4 and 51. The intracranial measurements were done in a small population of patients who had electrodes implanted for epilepsy monitoring at University Medical Center Utrecht, Netherlands.

The response delays in connected brain regions showed that transmission speeds in the human brain increase throughout childhood and even into early adulthood. They plateau around 30 to 40 years of age.

The team’s data indicate that adult transmission speeds were about two times faster compared to those typically found in children. Transmission speeds also were typically faster in 30- or 40-year-old subjects compared to teenagers.

Brain transmission speed is measured in milliseconds, a unit of time equal to one-thousandth of a second. For example, the researchers measured the neuronal speed of a 4-year-old patient at 45 milliseconds for a signal to travel from the frontal to parietal regions of the brain. In a 38-year-old patient, the same pathway was measured at 20 milliseconds. For comparison, the blink of an eye takes about 100 to 400 milliseconds.

The researchers are working to characterise electrical stimulation-driven connectivity in the human brain. One of the next steps is to better understand how transmission speeds change with neurological diseases. They are collaborating with paediatric neurosurgeons and neurologists to understand how diseases change transmission speeds compared to what would be considered within the normal range for a certain age group.

Source: Mayo Clinic