̽��ֱ�� of Cambridge - Fudan ̽��ֱ��

Adolescents who sleep longer perform better at cognitive tasks

cjb250 — Tue, 22 Apr 2025 15:00:23 +0000

But the study of adolescents in the US also showed that even those with better sleeping habits were not reaching the amount of sleep recommended for their age group.

Sleep plays an important role in helping our bodies function. It is thought that while we are asleep, toxins that have built up in our brains are cleared out, and brain connections are consolidated and pruned, enhancing memory, learning, and problem-solving skills. Sleep has also been shown to boost our immune systems and improve our mental health.

During adolescence, our sleep patterns change. We tend to start going to bed later and sleeping less, which affects our body clocks. All of this coincides with a period of important development in our brain function and cognitive development. ̽��ֱ��American Academy of Sleep Medicine says that the ideal amount of sleep during this period is between eight- and 10-hours’ sleep.

Professor Barbara Sahakian from the Department of Psychiatry at the ̽��ֱ�� of Cambridge said: “Regularly getting a good night’s sleep is important in helping us function properly, but while we know a lot about sleep in adulthood and later life, we know surprisingly little about sleep in adolescence, even though this is a crucial time in our development. How long do young people sleep for, for example, and what impact does this have on their brain function and cognitive performance?”

Studies looking at how much sleep adolescents get usually rely on self-reporting, which can be inaccurate. To get around this, a team led by researchers at Fudan ̽��ֱ��, Shanghai, and the ̽��ֱ�� of Cambridge turned to data from the Adolescent Brain Cognitive Development (ABCD) Study, the largest long-term study of brain development and child health in the United States.

As part of the ABCD Study, more than 3,200 adolescents aged 11-12 years old had been given FitBits, allowing the researchers to look at objective data on their sleep patterns and to compare it against brain scans and results from cognitive tests. ̽��ֱ��team double-checked their results against two additional groups of 13-14 years old, totalling around 1,190 participants. ̽��ֱ��results are published today in Cell Reports.

̽��ֱ��team found that the adolescents could be divided broadly into one of three groups:

Group One, accounting for around 39% of participants, slept an average (mean) of 7 hours 10 mins. They tended to go to bed and fall asleep the latest and wake up the earliest.

Group Two, accounting for 24% of participants, slept an average of 7 hours 21 mins. They had average levels across all sleep characteristics.

Group Three, accounting for 37% of participants, slept an average of 7 hours 25 mins. They tended to go to bed and fall asleep the earliest and had lower heart rates during sleep.

Although the researchers found no significant differences in school achievement between the groups, when it came to cognitive tests looking at aspects such as vocabulary, reading, problem solving and focus, Group Three performed better than Group Two, which in turn performed better than Group One.

Group Three also had the largest brain volume and best brain functions, with Group One the smallest volume and poorest brain functions.

Professor Sahakian said: “Even though the differences in the amount of sleep that each group got was relatively small, at just over a quarter-of-an-hour between the best and worst sleepers, we could still see differences in brain structure and activity and in how well they did at tasks. This drives home to us just how important it is to have a good night’s sleep at this important time in life.”

First author Dr Qing Ma from Fudan ̽��ֱ�� said: “Although our study can’t answer conclusively whether young people have better brain function and perform better at tests because they sleep better, there are a number of studies that would support this idea. For example, research has shown the benefits of sleep on memory, especially on memory consolidation, which is important for learning.”

̽��ֱ��researchers also assessed the participants’ heart rates, finding that Group Three had the lowest heart rates across the sleep states and Group One the highest. Lower heart rates are usually a sign of better health, whereas higher rates often accompany poor sleep quality like restless sleep, frequent awakenings and excessive daytime sleepiness.

Because the ABCD Study is a longitudinal study – that is, one that follows its participants over time – the team was able to show that the differences in sleep patterns, brain structure and function, and cognitive performance, tended be present two years before and two years after the snapshot that they looked at.

Senior author Dr Wei Cheng from Fudan ̽��ֱ�� added: “Given the importance of sleep, we now need to look at why some children go to bed later and sleep less than others. Is it because of playing videogames or smartphones, for example, or is it just that their body clocks do not tell them it’s time to sleep until later?”

̽��ֱ��research was supported by the National Key R&D Program of China, National Natural Science Foundation of China, National Postdoctoral Foundation of China and Shanghai Postdoctoral Excellence Program. ̽��ֱ��ABCD Study is supported by the National Institutes of Health.

Reference

Ma, Q et al. Neural correlates of device-based sleep characteristics in adolescents. Cell Reports; 22 Apr 2025; DOI: 10.1016/j.celrep.2025.115565

Adolescents who sleep for longer – and from an earlier bedtime – than their peers tend to have improved brain function and perform better at cognitive tests, researchers from the UK and China have shown.

Even though the differences in the amount of sleep that each group got was relatively small, we could still see differences in brain structure and activity and in how well they did at tasks

Barbara Sahakian

harpazo_hope (Getty Images)

Teenager asleep and wrapped in a blanket

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Loneliness linked to higher risk of heart disease and stroke and susceptibility to infection

cjb250 — Fri, 03 Jan 2025 10:00:00 +0000

Researchers from the UK and China drew this conclusion after studying proteins from blood samples taken from over 42,000 adults recruited to the UK Biobank. Their findings are published today in the journal Nature Human Behaviour.

Social relationships play an important role in our wellbeing. Evidence increasingly demonstrates that both social isolation and loneliness are linked to poorer health and an early death. Despite this evidence, however, the underlying mechanisms through which social relationships impact health remain elusive.

One way to explore biological mechanisms is to look at proteins circulating in the blood. Proteins are molecules produced by our genes and are essential for helping our bodies function properly. They can also serve as useful drug targets, allowing researchers to develop new treatments to tackle diseases.

A team led by scientists at the ̽��ֱ�� of Cambridge, UK, and Fudan ̽��ֱ��, China, examined the ‘proteomes’ – the suite of proteins – in blood samples donated by over 42,000 adults aged 40-69 years who are taking part in the UK Biobank. This allowed them to see which proteins were present in higher levels among people who were socially isolated or lonely, and how these proteins were connected to poorer health.

̽��ֱ��team calculated social isolation and loneliness scores for individuals. Social isolation is an objective measure based on, for example, whether someone lives alone, how frequently they have contact with others socially, and whether they take part in social activities. Loneliness, on the other hand, is a subjective measure based on whether an individual feels lonely.

When they analysed the proteomes and adjusted for factors such as age, sex and socioeconomic background, the team found 175 proteins associated with social isolation and 26 proteins associated with loneliness (though there was substantial overlap, with approximately 85% of the proteins associated with loneliness being shared with social isolation). Many of these proteins are produced in response to inflammation, viral infection and as part of our immune responses, as well as having been linked to cardiovascular disease, type 2 diabetes, stroke, and early death.

̽��ֱ��team then used a statistical technique known as Mendelian randomization to explore the causal relationship between social isolation and loneliness on the one hand, and proteins on the other. Using this approach, they identified five proteins whose abundance was caused by loneliness.

Dr Chun Shen from the Department of Clinical Neurosciences at the ̽��ֱ�� of Cambridge and the Institute of Science and Technology for Brain-Inspired Intelligence, Fudan ̽��ֱ��, said: “We know that social isolation and loneliness are linked to poorer health, but we’ve never understood why. Our work has highlighted a number of proteins that appear to play a key role in this relationship, with levels of some proteins in particular increasing as a direct consequence of loneliness.

Professor Jianfeng Feng from the ̽��ֱ�� of Warwick said: "There are more than 100,000 proteins and many of their variants in the human body. AI and high throughput proteomics can help us pinpoint some key proteins in prevention, diagnosis, treatment and prognosis in many human diseases and revolutionise the traditional view of human health.

" ̽��ֱ��proteins we’ve identified give us clues to the biology underpinning poor health among people who are socially isolated or lonely, highlighting why social relationships play such an important part in keeping us healthy.”

One of the proteins produced in higher levels as a result of loneliness was ADM. Previous studies have shown that this protein plays a role in responding to stress and in regulating stress hormones and social hormones such as oxytocin – the so-called ‘love hormone’ – which can reduce stress and improve mood.

̽��ֱ��team found a strong association between ADM and the volume of the insula, a brain hub for interoception, our ability to sense what's happening inside our body – the greater the ADM levels, the smaller the volume of this region. Higher ADM levels were also linked to lower volume of the left caudate, a region involved in emotional, reward, and social processes. In addition, higher levels of ADM were linked to increased risk of early death.

Another of the proteins, ASGR1, is associated with higher cholesterol and an increased risk of cardiovascular disease, while other identified proteins play roles in the development of insulin resistance, atherosclerosis (‘furring’ of the arteries) and cancer progression, for example.

Professor Barbara Sahakian from the Department of Psychiatry at the ̽��ֱ�� of Cambridge said: “These findings drive home the importance of social contact in keeping us well. More and more people of all ages are reporting feeling lonely. That’s why the World Health Organization has described social isolation and loneliness as a ‘global public health concern’. We need to find ways to tackle this growing problem and keep people connected to help them stay healthy.”

̽��ֱ��research was supported by the National Natural Sciences Foundation of China, China Postdoctoral Science Foundation, Shanghai Rising-Star Program, National Key R&D Program of China, Shanghai Municipal Science and Technology Major Project, 111 Project, Shanghai Center for Brain Science and Brain-Inspired Technology, and Zhangjiang Lab.

Reference
Shen, C et al. Plasma proteomic signatures of social isolation and loneliness associated with morbidity and mortality. Nat Hum Behav; 3 Jan 2025; DOI: 10.1038/s41562-024-02078-1

Interactions with friends and family may keep us healthy because they boost our immune system and reduce our risk of diseases such as heart disease, stroke and type 2 diabetes, new research suggests.

More and more people of all ages are reporting feeling lonely. We need to find ways to tackle this growing problem and keep people connected to help them stay healthy

Barbara Sahakian

Noah Silliman

Person looking out through window

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Birth by C-section more than doubles odds of measles vaccine failure

jg533 — Mon, 13 May 2024 09:01:04 +0000

A study by the ̽��ֱ�� of Cambridge, UK, and Fudan ̽��ֱ��, China, has found that a single dose of the measles jab is up to 2.6 times more likely to be completely ineffective in children born by C-section, compared to those born naturally.

Failure of the vaccine means that the child’s immune system does not produce antibodies to fight against measles infection, so they remain susceptible to the disease.

A second measles jab was found to induce a robust immunity against measles in C-section children.

Measles is a highly infectious disease, and even low vaccine failure rates can significantly increase the risk of an outbreak.

A potential reason for this effect is linked to the development of the infant’s gut microbiome – the vast collection of microbes that naturally live inside the gut. Other studies have shown that vaginal birth transfers a greater variety of microbes from mother to baby, which can boost the immune system.

“We’ve discovered that the way we’re born - either by C-section or natural birth - has long-term consequences on our immunity to diseases as we grow up,” said Professor Henrik Salje in the ̽��ֱ�� of Cambridge’s Department of Genetics, joint senior author of the report.

He added: “We know that a lot of children don't end up having their second measles jab, which is dangerous for them as individuals and for the wider population.

“Infants born by C-section are the ones we really want to be following up to make sure they get their second measles jab, because their first jab is much more likely to fail.”

̽��ֱ��results are published today in the journal Nature Microbiology.

At least 95% of the population needs to be fully vaccinated to keep measles under control but the UK is well below this, despite the Measles, Mumps and Rubella (MMR) vaccine being available through the NHS Routine Childhood Immunisation Programme.

An increasing number of women around the world are choosing to give birth by caesarean section: in the UK a third of all births are by C-section, in Brazil and Turkey over half of all children are born this way.

“With a C-section birth, children aren’t exposed to the mother’s microbiome in the same way as with a vaginal birth. We think this means they take longer to catch up in developing their gut microbiome, and with it, the ability of the immune system to be primed by vaccines against diseases including measles,” said Salje.

To get their results, the researchers used data from previous studies of over 1,500 children in Hunan, China, which included blood samples taken every few weeks from birth to the age of 12. This allowed them to see how levels of measles antibodies in the blood change over the first few years of life, including following vaccination.

They found that 12% of children born via caesarean section had no immune response to their first measles vaccination, as compared to 5% of children born by vaginal delivery. This means that many of the children born by C-section did still mount an immune response following their first vaccination.

Two doses of the measles jab are needed for the body to mount a long-lasting immune response and protect against measles. According to the World Health Organisation, in 2022 only 83% of the world's children had received one dose of measles vaccine by their first birthday – the lowest since 2008.

Salje said: “Vaccine hesitancy is really problematic, and measles is top of the list of diseases we’re worried about because it’s so infectious.”

Measles is one of the world’s most contagious diseases, spread by coughs and sneezes. It starts with cold-like symptoms and a rash, and can lead to serious complications including blindness, seizures, and death.

Before the measles vaccine was introduced in 1963, there were major measles epidemics every few years causing an estimated 2.6 million deaths each year.

̽��ֱ��research was funded by the National Natural Science Foundation of China.

Reference

Wang, W et al: ‘Dynamics of measles immunity from birth and following vaccination.’ Nature Microbiology, 13 May 2024. DOI: 10.1038/s41564-024-01694-x

Researchers say it is vital that children born by caesarean section receive two doses of the measles vaccine for robust protection against the disease.

CHBD / E+ / Getty Images

Very sick 5 year old little boy fighting measles infection, boy is laying in bed under the blanket with an agonizing expression, boy is covered with rash caused by virus.

Yes

Healthy lifestyle can help prevent depression – and new research may explain why

cjb250 — Mon, 11 Sep 2023 15:00:41 +0000

In research published today in Nature Mental Health, an international team of researchers, including from the ̽��ֱ�� of Cambridge and Fudan ̽��ֱ��, looked at a combination of factors including lifestyle factors, genetics, brain structure and our immune and metabolic systems to identify the underlying mechanisms that might explain this link.

According to the World Health Organization, around one in 20 adults experiences depression, and the condition poses a significant burden on public health worldwide. ̽��ֱ��factors that influence the onset of depression are complicated and include a mixture of biological and lifestyle factors.

To better understand the relationship between these factors and depression, the researchers turned to UK Biobank, a biomedical database and research resource containing anonymised genetic, lifestyle and health information about its participants.

By examining data from almost 290,000 people – of whom 13,000 had depression – followed over a nine-year period, the team was able to identify seven healthy lifestyle factors linked with a lower risk of depression. These were:

moderate alcohol consumption
healthy diet
regular physical activity
healthy sleep
never smoking
low-to-moderate sedentary behaviour
frequent social connection

Of all of these factors, having a good night’s sleep – between seven and nine hours a night – made the biggest difference, reducing the risk of depression, including single depressive episodes and treatment-resistant depression, by 22%.

Frequent social connection, which in general reduced the risk of depression by 18%, was the most protective against recurrent depressive disorder.

Moderate alcohol consumption decreased the risk of depression by 11%, healthy diet by 6%, regular physical activity by 14%, never smoking by 20%, and low-to-moderate sedentary behaviour by 13%.

Based on the number of healthy lifestyle factors an individual adhered to, they were assigned to one of three groups: unfavourable, intermediate, and favourable lifestyle. Individuals in the intermediate group were around 41% less likely to develop depression compared to those in the unfavourable lifestyle, while those in the favourable lifestyle group were 57% less likely.

̽��ֱ��team then examined the DNA of the participants, assigning each a genetic risk score. This score was based on the number of genetic variants an individual carried that have a known link to risk of depression. Those with the lowest genetic risk score were 25% less likely to develop depression when compared to those with the highest score – a much smaller impact than lifestyle.

In people at high, medium, and low genetic risk for depression, the team further found that a healthy lifestyle can cut the risk of depression. This research underlines the importance of living a healthy lifestyle for preventing depression, regardless of a person's genetic risk.

Professor Barbara Sahakian, from the Department of Psychiatry at the ̽��ֱ�� of Cambridge, said: “Although our DNA – the genetic hand we’ve been dealt – can increase our risk of depression, we’ve shown that a healthy lifestyle is potentially more important.

“Some of these lifestyle factors are things we have a degree control over, so trying to find ways to improve them – making sure we have a good night’s sleep and getting out to see friends, for example – could make a real difference to people’s lives.”

To understand why a healthy lifestyle might reduce the risk of depression, the team studied a number of other factors.

First off, they examined MRI brain scans from just under 33,000 participants and found a number of regions of the brain where a larger volume – more neurons and connections – was linked to a healthy lifestyle. These included the pallidum, thalamus, amygdala and hippocampus.

Next, the team looked for markers in the blood that indicated problems with the immune system or metabolism (how we process food and produce energy). Among those markers found to be linked to lifestyle were the C-reactive protein, a molecule produced in the body in response to stress, and triglycerides, one of the primary forms of fat that the body uses to store energy for later.

These links are supported by a number of previous studies. For example, exposure to stress in life can affect how well we are able to regulate blood sugar, which may lead to a deterioration of immune function and accelerate age-related damage to cells and molecules in the body. Poor physical activity and lack of sleep can damage the body’s ability to respond to stress. Loneliness and lack of social support have been found to increase the risk of infection and increase markers of immune deficiency.

̽��ֱ��team found that the pathway from lifestyle to immune and metabolic functions was the most significant. In other words, a poorer lifestyle impacts on our immune system and metabolism, which in turn increases our risk of depression.

Dr Christelle Langley, also from the Department of Psychiatry at the ̽��ֱ�� of Cambridge, said: “We’re used to thinking of a healthy lifestyle as being important to our physical health, but it’s just as important for our mental health. It’s good for our brain health and cognition, but also indirectly by promoting a healthier immune system and better metabolism.”

Professor Jianfeng Feng, from Fudan ̽��ֱ�� and Warwick ̽��ֱ��, added: “We know that depression can start as early as in adolescence or young adulthood, so educating young people on the importance of a healthy lifestyle and its impact on mental health should begin in schools.”

This study was supported by grants from organisations including the National Natural Science Foundation of China and the Ministry of Science, China*.

Reference
Zhao, Y & Yang, L et al. ̽��ֱ��brain structure, immunometabolic and genetic mechanisms underlying the association between lifestyle and depression. Nature Mental Health; 11 Sept 2023; DOI: 10.1038/s44220-023-00120-1

*A full list of funders can be found in the paper.

A healthy lifestyle that involves moderate alcohol consumption, a healthy diet, regular physical activity, healthy sleep and frequent social connection, while avoiding smoking and too much sedentary behaviour, reduces the risk of depression, new research has found.

Although our DNA – the genetic hand we’ve been dealt – can increase our risk of depression, we’ve shown that a healthy lifestyle is potentially more important.

Barbara Sahakian

Sweet Life

A group of people standing around a table with plates of food

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Reduced grey matter in frontal lobes linked to teenage smoking and nicotine addiction

fpjl2 — Tue, 15 Aug 2023 15:02:04 +0000

Levels of grey matter in two parts of the brain may be linked to a desire to start smoking during adolescence and the strengthening of nicotine addiction, a new study has shown.

A team of scientists, led by the universities of Cambridge and Warwick in the UK and Fudan ̽��ֱ�� in China, analysed brain imaging and behavioural data of over 800 young people at the ages of 14, 19 and 23.

They found that, on average, teenagers who started smoking by 14 years of age had markedly less grey matter in a section of the left frontal lobe linked to decision-making and rule-breaking.

Grey matter is the brain tissue that processes information, and contains all of the organ’s neurons. While brain development continues into adulthood, grey matter growth peaks before adolescence.

Low grey matter volume in the left side of the ventromedial prefrontal cortex may be an “inheritable biomarker” for nicotine addiction, say researchers – with implications for prevention and treatment.

In addition, the scientists found that the opposite, right part of the same brain region also had less grey matter in smokers.

Importantly, loss of grey matter in the right prefrontal cortex appears to speed up only after someone has started smoking. This region is linked to the seeking of sensations.

̽��ֱ��team argue that less grey matter in the left forebrain could lower cognitive function and lead to “disinhibition”: impulsive, rule-breaking behaviour arising from a limited ability to consider consequences. This may increase the chances of smoking at a young age.

Once a nicotine habit takes hold, grey matter in the right frontal lobe shrinks, which may weaken control over smoking by affecting 'hedonic motivation': the way pleasure is sought and managed. Excessive loss of grey matter in the right brain was also linked to binge drinking and marijuana use.

Taken together, the findings point to a damaged “neurobehavioural mechanism” that can lead to nicotine use starting early and becoming locked into long-term addiction, say researchers. ̽��ֱ��study used data from the IMAGEN project and is published in the journal Nature Communications.

“Smoking is perhaps the most common addictive behaviour in the world, and a leading cause of adult mortality,” said Prof Trevor Robbins, co-senior author from Cambridge’s Department of Psychology.

“ ̽��ֱ��initiation of a smoking habit is most likely to occur during adolescence. Any way of detecting an increased chance of this, so we can target interventions, could help save millions of lives.”

Annual deaths from cigarettes are expected to reach eight million worldwide by the end of the decade. Currently, one in five adult deaths each year are attributed to smoking in the US alone.

“In our study, reduced grey matter in the left prefrontal cortex is associated with increased rule-breaking behaviour as well as early smoking experiences. It could be that this rule-breaking leads to the violation of anti-smoking norms,” said Robbins.

Co-author Prof Barbara Sahakian from Cambridge’s Department of Psychiatry said: “ ̽��ֱ��ventromedial prefrontal cortex is a key region for dopamine, the brain’s pleasure chemical. As well as a role in rewarding experiences, dopamine has long been believed to affect self-control.

“Less grey matter across this brain region may limit cognitive function, leading to lower self-control and a propensity for risky behaviour, such as smoking.”

̽��ֱ��study used data gathered by the IMAGEN project from sites in four European countries: UK, Germany, France and Ireland. ̽��ֱ��researchers compared brain imaging data for those who had smoked by age 14 with those who had not, and repeated this for the same participants at ages 19 and 23.

Those with smoking experience by 14 years of age had significantly less grey matter in the left prefrontal cortex, on average. Additionally, those who started smoking by age 19 also had less grey matter in their left prefrontal cortex at 14, indicating a potential causal influence.

̽��ֱ��scientists also looked at the right ventromedial prefrontal cortex. Grey matter loss occurs in everyone as they age. However, those who smoked from age 14 as well as those smoking from age 19 both ended up with excessive grey matter loss in the right frontal lobe.

For the right prefrontal cortex, 19-year-old smokers who did not start during adolescence had similar grey matter levels at age 14 to those who never smoked at all. This suggests a rapid reduction in the right ventromedial prefrontal cortex only begins with the onset of smoking.

Data at age 23 showed that grey matter volume in the right prefrontal cortex shrank at a faster pace in those who continued to smoke, suggesting an influence of smoking itself on prefrontal function.

Researchers also analysed data from two questionnaires completed by participants to investigate the personality traits of novelty seeking and sensation seeking.

“Both questionnaires examine the pursuit of thrilling experiences, but they measure distinct behaviours,” said Robbins. “ ̽��ֱ��sensation seeking scale focuses on pleasurable experiences, while the novelty seeking questionnaire includes items on impulsiveness and rule-breaking.”

Less grey matter in the left prefrontal cortex was associated with novelty seeking, particularly disorderly and rule-breaking behaviour, while reduced grey matter volume in the right prefrontal cortex was linked to sensation seeking only.

Lead author Prof Tianye Jia from Fudan ̽��ֱ�� added: “Less grey matter in the left frontal lobes is linked to behaviours that increase the likelihood of smoking in adolescence.

“Smokers then experience excessive loss of grey matter in the right frontal lobes, which is linked to behaviours that reinforce substance use. This may provide a causal account of how smoking is initiated in young people, and how it turns into dependence.”

Reference:
Jia, Tianye; Xiang, Shintong et al. Association between vmPFC gray matter volume and smoking initiation in adolescents. Nature Communications; 15 Aug 2023; DOI: 10.1038/s41467-023-40079-2

Findings may demonstrate a brain and behavioural basis for how nicotine addiction is initiated and then takes hold in early life, say scientists.

Smoking is perhaps the most common addictive behaviour in the world, and a leading cause of adult mortality

Trevor Robbins

Young people smoking

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Problems with ‘pruning’ brain connections linked to adolescent mental health disorders

cjb250 — Mon, 24 Apr 2023 15:00:34 +0000

̽��ֱ��findings, from an international collaboration, led by researchers in the UK, China and Germany, may help explain why people are often affected by more than one mental health disorder, and may in future help identify those at greatest risk.

One in seven adolescents (aged 10-19 years old) worldwide experiences mental health disorders, according to the World Health Organization (WHO). Depression, anxiety and behavioural disorders, such as attention deficit hyperactivity disorder (ADHD), are among the leading causes of illness and disability among young people, and adolescents will commonly have more than one mental health disorder.

Many mental health problems emerge during adolescence. Among these are disorders such as depression and anxiety, which manifest as ‘internalising’ symptoms, including low mood and worrying. Other conditions such as attention deficit hyperactivity disorder (ADHD) manifest as ‘externalising’ symptoms, such as impulsive behaviour.

Professor Barbara Sahakian from the Department of Psychiatry at the ̽��ֱ�� of Cambridge said: “Young people often experience multiple mental health disorders, beginning in adolescence and continuing – and often transforming – into adult life. This suggests that there’s a common brain mechanism that could explain the onset of these mental health disorders during this critical time of brain development.”

In a study published today in Nature Medicine, the researchers say they have identified a characteristic pattern of brain activity among these adolescents, which they have termed the ‘neuropsychopathological factor’, or NP factor for short.

̽��ֱ��team examined data from 1,750 adolescents, aged 14 years, from the IMAGEN cohort, a European research project examining how biological, psychological, and environmental factors during adolescence may influence brain development and mental health. In particular, they examined imaging data from brain scans taken while participants took part in cognitive tasks, looking for patterns of brain connectivity – in other words, how different regions of the brain communicate with each other.

Adolescents who experienced mental health problems – regardless of whether their disorder was one of internalising or externalising symptoms, or whether they experienced multiple disorders – showed similar patterns of brain activity. These patterns – the NP factor – were largely apparent in the frontal lobes, the area at the front of the brain responsible for executive function which, among other functions, controls flexible thinking, self-control and emotional behaviour.

̽��ֱ��researchers confirmed their findings by replicating them in 1,799 participants from the ABCD Study in the USA, a long-term study of brain development and child health, and by studying patients who had received psychiatric diagnoses.

When the team looked at genetic data from the IMAGEN cohort, they found that the NP factor was strongest in individuals who carried a particular variant of the gene IGSF11 that has been previously associated with multiple mental health disorders. This gene is known to play an important role in synaptic pruning, a process whereby unnecessary brain connections – synapses – are discarded. Problems with pruning may particularly affect the frontal lobes, since these regions are the last brain areas to complete development in adolescents and young adults.

Dr Tianye Jia from the Institute of Science and Technology for Brain-Inspired Intelligence, Fudan ̽��ֱ��, Shanghai, China and the Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK said: “As we grow up, our brains make more and more connections. This is a normal part of our development. But too many connections risk making the brain inefficient. Synaptic pruning helps ensure that brain activity doesn’t get drowned out in ‘white noise’.

“Our research suggests that when this important pruning process is disrupted, it affects how brain regions talk to each other. As this impact is seen most in the frontal lobes, this then has implications for mental health.”

̽��ֱ��researchers say that the discovery of the NP factor could help identify those young people at greatest risk of compounding mental health problems.

Professor Jianfeng Feng from Fudan ̽��ֱ�� in Shanghai, China, and the ̽��ֱ�� of Warwick, UK, said: “We know that many mental health disorders begin in adolescence and that individuals who develop one disorder are at increased risk of developing other disorders, too. By examining brain activity and looking for this NP factor, we might be able to detect those at greatest risk sooner, offering us more opportunity to intervene and reduce this risk.”

Funders included: the National Natural Science Foundation of China, European Union, National Institute for Health & Care Research (UK) and National Institutes of Health (NIH, USA).*

Reference
Chao Xie et al. A shared neural basis underlying psychiatric comorbidity. Nat Med; 24 Apr 2023: DOI: 10.1038/s41591-023-02317-4

*A full list of funders can be found in the paper.

Problems with the brain’s ability to ‘prune’ itself of unnecessary connections may underlie a wide range of mental health disorders that begin during adolescence, according to research published today.

Young people often experience multiple mental health disorders, beginning in adolescence and continuing – and often transforming – into adult life

Barbara Sahakian

Warren Wong

Teenager sitting near graffiti

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Social isolation may impact brain volume in regions linked to higher risk of dementia

cjb250 — Wed, 08 Jun 2022 20:00:16 +0000

“Social isolation is a serious yet underrecognized public health problem that is often associated with old age,” said study author Professor Jianfeng Feng of Fudan ̽��ֱ�� in Shanghai, China. “In the context of the COVID-19 pandemic, social isolation, or the state of being cut off from social networks, has intensified. It’s more important than ever to identify people who are socially isolated and provide resources to help them make connections in their community.”

̽��ֱ��study looked at over 460,000 people across the United Kingdom with an average age of 57 at the beginning of the study who were followed for nearly 12 years before the pandemic. Of those, almost 42,000 (9%) reported being socially isolated, and 29,000 (6%) felt lonely. During the study, almost 5,000 developed dementia.

Researchers collected survey data from participants, along with a variety of physical and biological measurements, including MRI data. Participants also took thinking and memory tests to assess their cognitive function. For social isolation, people were asked three questions about social contact: whether they lived with others; whether they had visits with friends or family at least once a month; and whether they participated in social activities such as clubs, meetings or volunteer work at least once a week. People were considered socially isolated if they answered no to at least two questions.

Of the 42,000 people with social isolation, 649 (1.55%) developed dementia, compared to 4,349 (1.03%) of those people who were not socially isolated.

After adjusting for factors including age, sex, socioeconomic status, alcohol intake and smoking, and other conditions like depression and loneliness, researchers found that socially isolated individuals had lower volume in the brain’s gray matter in various regions involved with learning and thinking. Researchers found that people who were socially isolated were 26% more likely to develop dementia than those with no social isolation. Researchers also looked at loneliness, but after adjusting, saw no strong correlation with developing dementia.

Professor Barbara Sahakian from the Department of Psychiatry at the ̽��ֱ�� of Cambridge, a study co-author, added: “People who reported high levels of social isolation were more likely to show significant differences in brain volume, in regions that we know as also associated with cognition problems and risk of dementia. This is very concerning and suggests to us that social isolation may be an early indicator of an increased risk of dementia.”

People who reported higher levels of social isolation were more likely to have lower gray matter volume in areas of the brain associated with learning and thinking. Overall, the results showed that lower gray matter volumes were associated with higher social isolation.

A limitation of the study was that participants reported fewer health conditions and were less likely to live alone than the general population, so the results may not apply to the general population.

̽��ֱ��study was a collaboration between Fudan ̽��ֱ��, the ̽��ֱ�� of Cambridge and the ̽��ֱ�� of Warwick. It was supported by the Chinese Ministry of Science and Technology, National Natural Sciences Foundation of China, the municipal government of Shanghai, ZJ Lab, Shanghai Center for Brain Science and Brain-Inspired Technology, and the Wellcome Trust.

Reference
Shen, C et al. Associations of Social Isolation and Loneliness With Later Dementia. Neurology; 8 June 2022; DOI: 10.1212/WNL.0000000000200583

Social isolation is linked to lower brain volume in areas related to cognition and a higher risk of dementia, according to research published today in Neurology. ̽��ֱ��study found that social isolation was linked to a 26% increased risk of dementia, separately from risk factors like depression and loneliness.

This is very concerning and suggests to us that social isolation may be an early indicator of an increased risk of dementia

Barbara Sahakian

Steven HWG

Elderly woman in the middle stages of Alzheimer

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Seven hours of sleep is optimal in middle and old age, say researchers

cjb250 — Thu, 28 Apr 2022 15:00:00 +0000

Sleep plays an important role in enabling cognitive function and maintaining good psychological health. It also helps keep the brain healthy by removing waste products. As we get older, we often see alterations in our sleep patterns, including difficulty falling asleep and staying asleep, and decreased quantity and quality of sleep. It is thought that these sleep disturbances may contribute to cognitive decline and psychiatric disorders in the ageing population.

In research published today in Nature Aging, scientists from the UK and China examined data from nearly 500,000 adults aged 38-73 years from the UK Biobank. Participants were asked about their sleeping patterns, mental health and wellbeing, and took part in a series of cognitive tests. Brain imaging and genetic data were available for almost 40,000 of the study participants.

By analysing these data, the team found that both insufficient and excessive sleep duration were associated with impaired cognitive performance, such as processing speed, visual attention, memory and problem-solving skills. Seven hours of sleep per night was the optimal amount of sleep for cognitive performance, but also for good mental health, with people experiencing more symptoms of anxiety and depression and worse overall wellbeing if they reported sleeping for longer or shorter durations.

̽��ֱ��researchers say one possible reason for the association between insufficient sleep and cognitive decline may be due to the disruption of slow-wave – ‘deep’ – sleep. Disruption to this type of sleep has been shown to have a close link with memory consolidation as well as the build-up of amyloid – a key protein which, when it misfolds, can cause ‘tangles’ in the brain characteristic of some forms of dementia. Additionally, lack of sleep may hamper the brain’s ability to rid itself of toxins.

̽��ֱ��team also found a link between the amount of sleep and differences in the structure of brain regions involved in cognitive processing and memory, again with greater changes associated with greater than or less than seven hours of sleep.

Having a consistent seven hours’ sleep each night, without too much fluctuation in duration, was also important to cognitive performance and good mental health and wellbeing. Previous studies have also shown that interrupted sleep patterns are associated with increased inflammation, indicating a susceptibility to age-related diseases in older people.

Professor Jianfeng Feng from Fudan ̽��ֱ�� in China said: “While we can’t say conclusively that too little or too much sleep causes cognitive problems, our analysis looking at individuals over a longer period of time appears to support this idea. But the reasons why older people have poorer sleep appear to be complex, influenced by a combination of our genetic makeup and the structure of our brains.”

̽��ֱ��researchers say the findings suggest that insufficient or excessive sleep duration may be a risk factor for cognitive decline in ageing. This is supported by previous studies that have reported a link between sleep duration and the risk of developing Alzheimer’s disease and dementia, in which cognitive decline is a hallmark symptom.

Professor Barbara Sahakian from the Department of Psychiatry at the ̽��ֱ�� of Cambridge, one of the study’s authors, said: “Getting a good night’s sleep is important at all stages of life, but particularly as we age. Finding ways to improve sleep for older people could be crucial to helping them maintain good mental health and wellbeing and avoiding cognitive decline, particularly for patients with psychiatric disorders and dementias.”

̽��ֱ��research was supported by the National Key R&D Program of China, the Shanghai Municipal Science and Technology Major Project, the Shanghai Center for Brain Science and Brain-Inspired Technology, the 111 Project, the National Natural Sciences Foundation of China and the Shanghai Rising Star Program.

Reference
Li, Y, Sahakian, BJ, et al. ̽��ֱ��brain structure and genetic mechanisms underlying the nonlinear association between sleep duration, cognition and mental health. Nature Aging; 28 Apr 2022l DOI: 10.1038/s43587-022-00210-2

Seven hours is the ideal amount of sleep for people in their middle age and upwards, with too little or too much sleep associated with poorer cognitive performance and mental health, say researchers from the ̽��ֱ�� of Cambridge and Fudan ̽��ֱ��.

Getting a good night’s sleep is important at all stages of life, but particularly as we age

Barbara Sahakian

Pornpak Khunatorn

Insomnia or sleep changes and disorders in elderly concept

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