Exercise reduces stress, improves cellular health in family caregivers
October 3, 2018
Science Daily/University of British Columbia
Exercising at least three times a week for six months reduced stress in a group of family caregivers and even appeared to lengthen a small section of their chromosomes that is believed to slow cellular aging.
"I am hoping that a new focus on the family caregiver will emerge out of this research," said Eli Puterman, a professor in the University of British Columbia's school of kinesiology and lead author of the study. "We need to design interventions that help caregivers take care of their bodies and their minds, and provide the type of support that's needed to maintain that long-term."
The population of seniors in the U.S., where Puterman and colleagues from the University of California conducted the study, is expected to nearly double by 2050. Younger family members will increasingly be providing this type of care and it can take a toll on their health.
"What caregivers need is support for healthy behaviours, because that is one of the first things to drop when you become a family caregiver," said Puterman. "The time to take care of yourself just goes out the window."
The researchers recruited physically inactive people who care for family members with Alzheimer's disease and dementia, and who reported feeling high levels of stress. The 68 participants were divided randomly into two groups. One group undertook 40 minutes of aerobic exercise three to five times per week, while the others were asked not to alter their level of activity. Those in the exercise group had free access to a gym, and a fitness coach for weekly conversations. Eighty-one per cent of them adhered to at least 120 minutes of exercise per week for the duration of the study.
At the end of the study, not only had the caregivers improved their cardiorespiratory fitness, reduced their body mass index and trimmed their waistlines, they also reported lower levels of perceived stress.
At the cellular level, the researchers observed longer telomeres in the participants' white blood cells after the program. Telomeres protect the ends of chromosomes, much like the aglets that protect the ends of shoelaces. Without them, chromosomes shorten to the point where they either die or enter a state called "senescence," in which they stop replicating. Senescent cells have been shown to be predictive of future health problems such as cardiovascular disease.
The study's findings suggest that in addition to reducing stress, exercise can slow or even reverse telomeric aging in a highly stressed, at-risk group.
https://www.sciencedaily.com/releases/2018/10/181003090339.htm
'Bugs' in the gut might predict dementia in the brain
January 30, 2019
Science Daily/American Heart Association
The makeup of bacteria and other microbes in the gut may have a direct association with dementia risk, according to preliminary research to be presented in Honolulu at the American Stroke Association's International Stroke Conference 2019, a world premier meeting for researchers and clinicians dedicated to the science and treatment of cerebrovascular disease.
Researchers studying the population of bacteria and microbes in the intestines, known as gut microbiota, have found these "bugs" impact risks for diseases of the heart and more. Japanese researchers studied 128 (dementia and non-dementia) patients' fecal samples and found differences in the components of gut microbiota in patients with the memory disorder suggesting that what's in the gut influences dementia risk much like other risk factors.
The analysis revealed that fecal concentrations of ammonia, indole, skatole and phenol were higher in dementia patients compared to those without dementia. But levels of Bacteroides -- organisms that normally live in the intestines and can be beneficial -- were lower in dementia patients.
"Although this is an observational study and we assessed a small number of the patients, the odds ratio is certainly high suggesting that gut bacteria may be a target for the prevention of dementia," said Naoki Saji, M.D., Ph.D., study author and vice director of the Center for Comprehensive Care and Research on Memory Disorders, National Center for Geriatrics and Gerontology in Japan.
https://www.sciencedaily.com/releases/2019/01/190130075751.htm
What you eat could impact your brain and memory
January 28, 2019
Science Daily/Iowa State University
High levels of a satiety hormone could decrease a person's likelihood of developing Alzheimer's disease. For individuals who have higher levels of the hormone, their chance of having mild cognitive impairment or Alzheimer's disease decreased by 65 percent.
You may be familiar with the saying, "You are what you eat," but did you know the food you eat could impact your memory?
Auriel Willette, assistant professor, and his team of researchers in Iowa State University's Department of Food Science and Human Nutrition discovered a satiety hormone that, at higher levels, could decrease a person's likelihood of developing Alzheimer's disease. A paper outlining the results of their study recently was accepted for publication in Neurobiology of Aging.
Using data from the Alzheimer's Disease Neuroimaging Initiative (ADNI), the researchers looked at the satiety hormone, Cholecystokinin (CCK), in 287 people. CCK is found in both the small intestines and the brain. In the small intestines, CCK allows for the absorption of fats and proteins. In the brain, CCK is located in the hippocampus, which is the memory-forming region of the brain, Willette said.
The researchers found for individuals who have higher CCK levels, their chance of having mild cognitive impairment, a precursor state to Alzheimer's disease, or Alzheimer's disease decreased by 65 percent.
"It will hopefully help to shed further light on how satiety hormones in the blood and brain affect brain function," Willette said.
Why CCK?
Alexandra Plagman, lead author and graduate student in nutritional science, said they chose to focus on CCK because it is highly expressed in memory formation. The researchers wanted to see if there was any significance between levels of CCK and levels of memory and gray matter in the hippocampus and other important areas.
They also looked p-tau and tau proteins, which are thought to be toxic to the brain, to see how these might impact CCK and memory. They found that as tau levels increased, higher CCK was no longer related to less memory decline.
The researchers hope this study will encourage others to look into the nutritional aspect of diets, versus just looking at caloric intake. Plagman already is looking at how diet impacts an individual's CCK levels through researching fasting glucose and ketone bodies.
"By looking at the nutritional aspect, we can tell if a certain diet could prevent Alzheimer's disease or prevent progression of the disease," Plagman said.
"The regulation of when and how much we eat can have some association with how good our memory is," Willette added. "Bottom line: what we eat and what our body does with it affects our brain."
https://www.sciencedaily.com/releases/2019/01/190128111705.htm
Sleep deprivation accelerates Alzheimer's brain damage
January 24, 2019
Science Daily/Washington University School of Medicine
A study in mice and people shows that sleep deprivation causes tau levels to rise and tau tangles to spread through the brain. Tau tangles are associated with Alzheimer's disease and brain damage.
Poor sleep has long been linked with Alzheimer's disease, but researchers have understood little about how sleep disruptions drive the disease.
Now, studying mice and people, researchers at Washington University School of Medicine in St. Louis have found that sleep deprivation increases levels of the key Alzheimer's protein tau. And, in follow-up studies in the mice, the research team has shown that sleeplessness accelerates the spread through the brain of toxic clumps of tau - a harbinger of brain damage and decisive step along the path to dementia.
These findings, published online Jan. 24 in the journal Science, indicate that lack of sleep alone helps drive the disease, and suggests that good sleep habits may help preserve brain health.
"The interesting thing about this study is that it suggests that real-life factors such as sleep might affect how fast the disease spreads through the brain," said senior author David Holtzman, MD, the Andrew B. and Gretchen P. Jones Professor and head of the Department of Neurology. "We've known that sleep problems and Alzheimer's are associated in part via a different Alzheimer's protein -- amyloid beta -- but this study shows that sleep disruption causes the damaging protein tau to increase rapidly and to spread over time."
Tau is normally found in the brain -- even in healthy people -- but under certain conditions it can clump together into tangles that injure nearby tissue and presage cognitive decline. Recent research at the School of Medicine has shown that tau is high in older people who sleep poorly. But it wasn't clear whether lack of sleep was directly forcing tau levels upward, or if the two were associated in some other way. To find out, Holtzman and colleagues including first authors Jerrah Holth, PhD, a staff scientist, and Sarah Fritschi, PhD, a former postdoctoral scholar in Holtzman's lab, measured tau levels in mice and people with normal and disrupted sleep.
Mice are nocturnal creatures. The researchers found that tau levels in the fluid surrounding brain cells were about twice as high at night, when the animals were more awake and active, than during the day, when the mice dozed more frequently. Disturbing the mice's rest during the day caused daytime tau levels to double.
Much the same effect was seen in people. Brendan Lucey, MD, an assistant professor of neurology, obtained cerebrospinal fluid -- which bathes the brain and spinal cord -- from eight people after a normal night of sleep and again after they were kept awake all night. A sleepless night caused tau levels to rise by about 50 percent, the researchers discovered.
Staying up all night makes people stressed and cranky and likely to sleep in the next chance they get. While it's hard to judge the moods of mice, they, too, rebounded from a sleepless day by sleeping more later. To rule out the possibility that stress or behavioral changes accounted for the changes in tau levels, Fritschi created genetically modified mice that could be kept awake for hours at a time by injecting them with a harmless compound. When the compound wears off, the mice return to their normal sleep-wake cycle -- without any signs of stress or apparent desire for extra sleep.
Using these mice, the researchers found that staying awake for prolonged periods causes tau levels to rise. Altogether, the findings suggest that tau is routinely released during waking hours by the normal business of thinking and doing, and then this release is decreased during sleep allowing tau to be cleared away. Sleep deprivation interrupts this cycle, allowing tau to build up and making it more likely that the protein will start accumulating into harmful tangles.
In people with Alzheimer's disease, tau tangles tend to emerge in parts of the brain important for memory -- the hippocampus and entorhinal cortex -- and then spread to other brain regions. As tau tangles mushroom and more areas become affected, people increasingly struggle to think clearly.
To study whether the spread of tau tangles is affected by sleep, the researchers seeded the hippocampi of mice with tiny clumps of tau and then kept the animals awake for long periods each day. A separate group of mice also was injected with tau tangles but was allowed to sleep whenever they liked. After four weeks, tau tangles had spread further in the sleep-deprived mice than their rested counterparts. Notably, the new tangles appeared in the same areas of the brain affected in people with Alzheimer's.
"Getting a good night's sleep is something we should all try to do," Holtzman said. "Our brains need time to recover from the stresses of the day. We don't know yet whether getting adequate sleep as people age will protect against Alzheimer's disease. But it can't hurt, and this and other data suggest that it may even help delay and slow down the disease process if it has begun."
The researchers also found that disrupted sleep increased release of synuclein protein, a hallmark of Parkinson's disease. People with Parkinson's -- like those with Alzheimer's -- often have sleep problems.
https://www.sciencedaily.com/releases/2019/01/190124141536.htm
Exercise may lessen fall risk for older adults with Alzheimer's
Study indicates exercise may decrease risk of falling for older adults who have Alzheimer's disease and mental health challenges
October 29, 2018
Science Daily/American Geriatrics Society
A research team decided to explore whether exercise could reduce the risk of falling among community-dwelling people with Alzheimer's Disease who also had neuropsychiatric symptoms.
Alzheimer's disease (AD) is a brain disease that causes changes that kill brain cells. AD is a type of dementia, which causes memory loss and problems with thinking and making decisions. People with AD and other forms of dementia have difficulties performing the daily activities others might consider routine.
Dementia takes a toll on those who live with it -- and it also places a burden on caregivers. Along with problems connected to memory, language, and decision-making, dementia can cause neuropsychiatric symptoms, such as depression, anxiety, changes in mood, increased irritability, and changes in personality and behavior. People who have AD/dementia also have twice the risk for falls compared to people without dementia. About 60 percent of older adults with dementia fall each year.
Researchers suggest that having neuropsychiatric symptoms might predict whether an older person with AD/dementia is more likely to have a fall. We also know that exercise can reduce the number of falls in older adults with dementia. However, we don't know very much about how neuropsychiatric symptoms may increase the risk of falls, and we know even less about how exercise may reduce the risk of falls for people with dementia and neuropsychiatric symptoms. A research team decided to explore whether exercise could reduce the risk of falling among community-dwelling people with AD who also had neuropsychiatric symptoms.
To learn more, the researchers reviewed a study that investigated the effects of an exercise program for older adults with AD (the FINALEX trial). The study included a range of people living with different stages of AD/dementia and with neuropsychiatric symptoms. Their findings were published in the Journal of the American Geriatrics Society.
The original FINALEX study examined and compared older adults who had home- or group-based exercise training with people who didn't exercise but who received regular care. The researchers learned that the people who exercised had a lower risk for falls than those who didn't exercise. There was also a higher risk for falls among those who had lower scores on psychological tests and who didn't exercise.
This study revealed that people with AD/dementia and neuropsychiatric symptoms such as depression and anxiety have a higher risk for falls. Exercise can reduce the risk of falling for older adults with these symptoms. Further studies are needed to confirm these results.
https://www.sciencedaily.com/releases/2018/10/181029135235.htm
Stress can impair memory, reduce brain size in middle age
October 25, 2018
Science Daily/University of Texas Health Science Center at San Antonio
Stress may be causing impaired memory and brain shrinkage in middle-age adults, even before symptoms of Alzheimer's or other dementia begin, according to a new study.
Adults in their 40s and 50s with higher levels of cortisol -- a hormone linked to stress -- performed worse on memory and other cognitive tasks than peers of the same age with average cortisol levels, research found. Higher cortisol in the blood also was associated with smaller brain volumes, according to the study, published Oct. 24 in Neurology, the medical journal of the American Academy of Neurology.
"In our quest to understand cognitive aging, one of the factors attracting significant interest and concern is the increasing stress of modern life," said study senior author Sudha Seshadri, M.D., professor of neurology at UT Health San Antonio and founding director of the university's Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases. "One of the things we know in animals is that stress can lead to cognitive decline. In this study, higher morning cortisol levels in a large sample of people were associated with worse brain structure and cognition."
The cognitive data are from 2,231 participants in the Framingham Heart Study, for which Dr. Seshadri is a senior investigator; 2,018 participants also underwent magnetic resonance imaging (MRI) to measure brain volume. The team included Framingham collaborators at Harvard Medical School; the National Heart, Lung, and Blood Institute; Boston University School of Medicine; the University of California, Davis, at Sacramento; and UT Health San Antonio.
Blood serum cortisol, which varies in level throughout the day, was measured in early morning (between 7:30 and 9 a.m.) in each fasting participant. The study featured a relatively young sample of male and female participants (mean age 48.5).
"Cortisol affects many different functions, so it is important to fully investigate how high levels of the hormone may affect the brain," said study lead author Justin B. Echouffo-Tcheugui, M.D., Ph.D., of Harvard Medical School. "While other studies have examined cortisol and memory, we believe our large, community-based study is the first to explore, in middle-aged people, fasting blood cortisol levels and brain volume, as well as memory and thinking skills."
Memory loss and brain shrinkage were found in the study's middle-age participants before the onset of any symptoms, Dr. Echouffo-Tcheugui noted. He said it is important for physicians to counsel people with higher cortisol levels on ways to reduce stress, such as getting enough sleep and engaging in moderate exercise.
"The faster pace of life today probably means more stress, and when we are stressed, cortisol levels increase because that is our fight-or-flight response," Dr. Seshadri said. "When we are afraid, when we are threatened in any way, our cortisol levels go up. This study adds to the prevailing wisdom that it's never too early to be mindful of reducing stress."
Findings were adjusted for factors including age, sex, smoking and body mass index. The team asked whether having APOE4, a genetic risk factor for cardiovascular disease and Alzheimer's disease, might be associated with higher cortisol level. This did not prove to be the case.
https://www.sciencedaily.com/releases/2018/10/181025084043.htm
Memory 'brainwaves' look the same in sleep and wakefulness
October 9, 2018
Science Daily/University of Birmingham
Identical brain mechanisms are responsible for triggering memory in both sleep and wakefulness, new research has shown.
The study sheds new light on the processes used by the brain to 'reactivate' memories during sleep, consolidating them so they can be retrieved later.
Although the importance of sleep in stabilising memories is a well-established concept, the neural mechanisms underlying this are still poorly understood.
In this study, published in Cell Reports, scientists have been able to show for the first time in humans that distinctive neural patterns in the brain which are triggered when remembering specific memories while awake, reappear during subsequent sleep.
The findings provide further evidence of the beneficial effects of sleep on memory formation.
Gaining a more sophisticated understanding of these mechanisms also enhances our understanding of how memories are formed. This could ultimately help scientists unravel the foundations of memory disorders such as Alzheimer's and lead to the development of memory boosting interventions.
Working in partnership with researchers at the Donders Institute, in Holland, the team used a technique called Targeted Memory Reactivation, which is known to enhance memory. In the experiment, previously learned information -- in this case foreign vocabulary -- is played back to a person while asleep.
Using electroencephalography, the brain signals of the study participants were recorded while learning and remembering the foreign vocabulary before sleep.
Subsequently, the researchers recorded the distinct neural pathways activated as the sleeping volunteers' brains reacted to hearing the words they had learned.
Comparing neural signals fired by the brain in each state, the researchers were able to show clear similarities in brain activity.
Dr Thomas Schreiner, of the University of Birmingham's School of Psychology, who led the research, says: "Although sleep and wakefulness might seem to have little in common, this study shows that brain activity in each of these states might be more similar than we previously thought. The neural activity we recorded provides further evidence for how important sleep is to memory and, ultimately, for our well-being."
"If we can better understand how memory really works, this could lead to new approaches for the treatment of memory disorders, such as Alzheimer's disease."
Dr Tobias Staudigl, of the Donders Institute, is co-lead author of the study. He said: "Understanding how memories are reactivated in different states also provides insight into how these memories could be altered -- which might for example be interesting in therapeutic settings."
The team are planning a follow-on study, devising ways to investigate spontaneous memory activation during sleep. Using advanced machine learning techniques, the researchers can record and interpret neural patterns in the brain, identifying where memories are activated without the need for an external prompt.
https://www.sciencedaily.com/releases/2018/10/181009115003.htm
How sleep deprivation hinders memory
October 2, 2018
Science Daily/Michigan State University
Researchers have conducted the largest experimentally controlled study on sleep deprivation to date, revealing just how detrimental operating without sleep can be in everything from bakers adding too much salt to cookies to surgeons botching surgeries.
While sleep deprivation research isn't new, the level at which distractions hinder sleep-deprived persons' memories and challenge them from successfully completing tasks was not clear until MSU's team quantified the impact.
"If you look at mistakes and accidents in surgery, public transportation and even operating nuclear power plants, lack of sleep is one of the primary reasons for human error," said Kimberly Fenn, associate professor of psychology and director of the MSU Sleep and Learning Lab. "There are many people in critical professions who are sleep-deprived. Research has found that nearly one-quarter of the people with procedure-heavy jobs have fallen asleep on the job."
Published in the Journal of Experimental Psychology: General, Fenn's research is unlike previous studies because of its focus on sleep deprivation's impact on completing tasks. These tasks, Fenn explained, involve following directions and include multiple steps.
Some basic errors, such as adding salt twice to a recipe, might not be so serious. However, some of the world's greatest human-caused catastrophes -- like Chernobyl, the Exxon Valdez oil spill and the Challenger explosion -- along with daily train and car accidents have sleep deprivation at least partially to blame, she said.
Fenn hopes that her lab's findings will shed light on how critical sleep is to completing any task, be it large or small.
"Every day, approximately 11 sponges are left inside of patients who have undergone surgery. That's 4,000 potentially dire missteps each year and an example of a procedural task gone terribly wrong that can result from sleep deprivation," Fenn said. "Our research suggests that sleep-deprived people shouldn't perform tasks in which they are interrupted -- or, only perform them for short periods."
To test sleep deprivation's impact on how people follow steps in a task, Fenn's team brought 234 people into the sleep lab at 10 p.m. That night, all of the participants worked on a sequence-based procedure that involved following a series of tasks in order. Periodically, they were interrupted and had to remember where they were in the procedure before picking up again. At midnight, half of the participants went home to sleep while the other half stayed awake all night at the lab. The next morning, everyone completed the procedure once again.
What Fenn's team found was a stark jump in errors for those who were sleep-deprived.
"All participants met performance criteria in the evening, but roughly 15 percent of participants in the sleep-deprived group failed in the morning, compared to 1 percent of those who slept," Fenn said. "Furthermore, sleep-deprived participants not only showed more errors than those who slept but also showed a progressive increase in errors associated with memory as they performed the task -- an effect not observed in those who slept. This shows that the sleep-deprived group experienced a great deal of difficulty remembering where they were in the sequence during interruptions."
Memory maintenance, the research found, was the real culprit keeping the sleep-deprived from completing tasks successfully. With hindered memory maintenance, it's much more difficult to pick up a task where you left off without missteps, Fenn explained.
Fenn also explained that distractions we face every day -- whether receiving a text message or simply answering a question -- are unavoidable but especially harmful to sleep-deprived people.
"Operating with reduced cognitive capacity has wide-ranging effects," Fenn said. "Students may pull all-nighters and not retain information for their exams. More worrisome, individuals working critical jobs may put themselves and other members of society at risk because of sleep deprivation. It simply cannot be overlooked."
https://www.sciencedaily.com/releases/2018/10/181002114027.htm
Dutch study estimates 1 in 2 women and 1 in 3 men set to develop dementia/parkinsonism/stroke
Preventive strategies could, in theory, more than halve lifetime risk for those aged 85-plus, say researchers
Science Daily/October 1, 2018
BMJ
One in two women and one in three men will likely be diagnosed with dementia, Parkinson's disease, or stroke in their lifetime, estimate Dutch researchers in an observational study.
But preventive strategies, which delay the onset of these common diseases by even a few years, could, in theory, cut this lifetime risk by between 20 and more than 50 per cent, they say.
The global costs of dementia, stroke, and parkinsonism are thought to amount to more than 2 per cent of the world's annual economic productivity (GDP), a figure that is set to rise steeply as life expectancy continues to increase.
But while the lifetime risks of other serious illnesses, such as breast cancer and heart disease are well known and used to raise public awareness, the same can't be said of dementia, stroke, parkinsonism, say the researchers.
To try and redress this, they tracked the neurological health of more than 12,000 people taking part in the Rotterdam Study between 1990 and 2016. This study has been looking at the incidence of, and influential factors behind, diseases of ageing in the general population.
All the participants were aged at least 45 years old when they were recruited, and more than half (just under 58 per cent) were women.
When they joined, participants were given a thorough health check, which was repeated every four years. Family doctor health records were also scrutinised for signs of disease or diagnoses arising between the four yearly check-ups.
Monitoring for dementia, parkinsonism, and stroke continued until death, or January 1 2016, whichever came first.
Between 1990 and 2016, 5291 people died, 3260 of whom had not been diagnosed with any neurological disease. But 1489 people were diagnosed with dementia, mostly Alzheimer's disease (just under 80%); 1285 had a stroke, nearly two thirds of which (65%) was caused by a blood clot (ischaemic); and 263 were diagnosed with parkinsonism.
A higher prevalence of high blood pressure, abnormal heart rhythm (atrial fibrillation), high cholesterol and type 2 diabetes was evident at the start of the monitoring period among those subsequently diagnosed with any of the three conditions.
Unsurprisingly, the risk of developing any of them rose steeply with age, but based on the data, the overall lifetime risk of a 45 year-old developing dementia, parkinsonism, or having a stroke was one in two for a woman (48%) and one in three for a man (36%).
This gender difference was largely driven by women being at heightened risk of developing dementia before men. But there were other gender differences in risk.
While 45 year-olds of both sexes had a similar lifetime risk of stroke, men were at substantially higher risk of having a stroke at younger ages than women.
And women were twice as likely as men to be diagnosed with both dementia and stroke during their lifetime.
The researchers calculated that if the onset of dementia, stroke, and parkinsonism were delayed by 1 to 3 years, the remaining lifetime risk could, in theory, be reduced by 20 per cent in 45 year-olds, and by more than 50 per cent in those aged 85+.
A delay of only a few years for one disease could also have a significant impact on combined lifetime risk, suggest the researchers.
"For instance, delaying dementia onset by 3 years has the potential to reduce lifetime risk of any disease by 15 per cent for men and women aged 45, and by up to 30 per cent for those aged 85 and older," they write.
The researchers point out that their study included only people of European ancestry with a relatively long life expectancy, so might not be applicable to other ethnicities/populations, and that they weren't able to measure the severity of any of the diagnosed conditions.
This research is observational, so no definitive conclusions can be drawn. But the researchers nevertheless conclude: "These findings strengthen the call for prioritising the focus on preventive interventions at population level which could substantially reduce the burden of common neurological diseases in the ageing population."
https://www.sciencedaily.com/releases/2018/10/181001190712.htm
Women twice as likely to suffer from severe depression after a stroke
January 28, 2019
Science Daily/King's College London
New research today published in the European Journal of Neurology has found that women are twice as likely to suffer from severe depression following a stroke than men.
The team of researchers from King's College London followed the progress of symptoms over five years after stroke onset in 2,313 people (1,275 men and 1,038 women).
They found that 20% of women suffered from severe depression compared to 10% of men. They also found varying patterns of symptom progression; that long-term increased symptoms of depression are associated with higher mortality rates; and that initially moderate symptoms in men tend to become worse over time.
Stroke is a life-threatening medical condition that occurs when blood flow to part of the brain is blocked. An estimated one in six people worldwide will have a stroke in their lifetime and there are more than 100,000 strokes in the UK every year. Although severity and symptoms are wide-ranging, about a third of all survivors experience depression following their stroke: approximately 400,000 people in the UK today.
Patients who had their first-ever stroke between 1998 and 2016 were recruited to the study from the South London Stroke Register (SLSR) and were monitored until July 2017. Participants' mental health was assessed using the Hospital Anxiety and Depression Scale (HADS) and cross-referenced with their physical health and socio-demographic data.
Lead author Dr Salma Ayis from the School of Population Health & Environmental Sciences at King's College London, said: "While we cannot pinpoint exactly why depression is more common among women, it could be that women draw more of their sense of self and self-worth from their social relationships and so are more sensitive to challenges in maintaining these. Also, as women live longer, they are more exposed to loneliness, poor physical health and loss of support, all of which could lead to depression.
"What is common to both sexes is the dramatic decrease in the likelihood of survival as depression symptoms increase. We believe therefore, that by monitoring symptoms of depression in stroke survivors and acting accordingly, clinicians may be able to provide better long-term care."
https://www.sciencedaily.com/releases/2019/01/190128191456.htm
For preterm infants, skin-to-skin contact affects hormone levels -- and may promote parental engagement
October 19, 2018
Science Daily/Wolters Kluwer Health
For premature infants in the neonatal intensive care unit (NICU), skin-to-skin contact with parents influences levels of hormones related to mother-infant attachment (oxytocin) and stress (cortisol) -- and may increase parents' level of engagement with their infants.
Promoting early contact and parental engagement might help to lessen the risk of neurodevelopmental delay associated with preterm birth and NICU care, according to the exploratory study by Dorothy J. Vittner, PhD, RN, CHPE, of University of Connecticut School of Nursing and colleagues. They write, "Parental touch, especially during skin-to-skin contact (SSC) has potential to reduce adverse consequences."
Study Attempts to Measure Benefits of Skin-to-Skin Contact for Preterm Infants
The pilot study included 28 preterm infants, average gestational age 33 weeks. All infants were in stable condition while receiving NICU care. Infants underwent periods of SSC on two consecutive days: once with the mother and once with the father. Saliva samples were collected from infants and parents to measure levels of oxytocin, a hormone that has been linked to maternal-infant attachment; and the stress-related hormone cortisol.
"Oxytocin facilitates social sensitivity and attunement necessary for developing relationships and nurturance for emotional and physical health," the researchers write. Cortisol plays an important role in the "fight or flight" reaction to fear or stress.
Levels of both hormones changed in response to SSC. "Oxytocin significantly increased and cortisol levels decreased for mothers, fathers, and infants during SSC as compared to baseline," Dr. Vittner and coauthors write. The changes indicate the "calming and beneficial impact of SSC for both parents and infants."
Parents also completed a questionnaire called the "PREEMI" (Parent Risk Evaluation and Engagement Model and Instrument) scale, designed to measure attachment between parents and their preterm infants. Overall PREEMI scores indicated a "moderate to high" level of parental engagement for all participants.
Increased oxytocin and decreased cortisol levels during SSC were associated with higher PREEMI scores by the time the infant was discharged from the hospital. "We believe these findings suggest that parents with a lower salivary cortisol as seen with SSC (decreased stress) may facilitate increased parental engagement," Dr. Vittner and colleagues write.
Mothers and fathers had similar increases in oxytocin during SSC. In mothers, the rise in oxytocin was related to increased parental engagement. Unexpectedly, however, increased oxytocin during SSC in fathers was negatively related to parental engagement. Dr. Vittner and colleagues note that for many fathers, the study SSC intervention was the first time they had held their infants.
The study provides new evidence of how SSC might work to promote attachment between parents and premature infants. "The changes in oxytocin and cortisol levels provide robust support to advocate for increased SSC during infancy, especially for the vulnerable infant in the NICU," the researchers write. They note that further studies will be needed to understand these relationships, and how they affect parent-infant relationships -- especially in overcoming the obstacles posed by having a premature infant who need NICU care.
The results also suggest that the PREEMI questionnaire can provide a "window into parent engagement," potentially useful in identifying parents who may need interventions to increase engagement with their premature infant. Dr. Vittner and coauthors conclude: "Uncovering the bio-behavioral basis of early parent-infant interactions is an important step in developing therapeutic modalities to improve infant health outcomes."
https://www.sciencedaily.com/releases/2018/10/181019100711.htm
Postpartum depression linked to mother's pain after childbirth
New study underscores importance of managing pain during recovery
Science Daily/October 14, 2018
American Society of Anesthesiologists
While childbirth pain has been linked to postpartum depression, the culprit may be the pain experienced by the mother following childbirth, rather than during the labor and delivery process.
Previous research has demonstrated the pain associated with giving birth may increase the risk of postpartum depression but has not specified which part of the labor process (e.g., before, during or after delivery) may be the source of the problem. This is the first study to differentiate postpartum pain from labor and delivery pain and identify it as a significant risk factor for postpartum depression.
"For many years, we have been concerned about how to manage labor pain, but recovery pain after labor and delivery often is overlooked," said Jie Zhou, M.D., M.B.A., lead author of the study and assistant professor of anesthesia at Brigham and Women's Hospital and Harvard Medical School, Boston. "Our research suggests we need to focus more on helping new mothers manage pain after the baby is born."
Symptoms of postpartum depression -- including extreme sadness, low energy, anxiety, crying episodes, irritability and changes in sleep or eating patterns -- affect about 1 in 9 women, according to the Centers for Disease Control and Prevention (CDC). Postpartum depression can lead to lower rates of breastfeeding and poor bonding with the baby.
In the study, Dr. Zhou's research group reviewed pain scores (from the start of labor to hospital discharge) for 4,327 first-time mothers delivering a single child vaginally or by cesarean delivery (C-section) at Brigham and Women's Hospital between June 1, 2015 and Dec. 31, 2017. They compared pain scores to the mothers' Edinburgh postnatal depression scale (EPDS) scores one week after delivery.
Dr. Zhou found postpartum depression was significantly associated with higher postpartum pain scores. Mothers with postpartum depression demonstrated more pain-related complaints during recovery and often needed additional pain medication. Women in the postpartum depression group were more likely to have delivered by C-section. They also had more reports of inadequate postpartum pain control.
A number of factors can contribute to postpartum depression. Researchers determined postpartum depression was higher among women who were overweight or obese; who suffered from a torn perineum (the area adjacent to the vaginal opening); who had a history of depression, anxiety or chronic pain; and whose babies were smaller and had lower Apgar scores, a scoring system used to assess the physical health of newborns one minute and five minutes after birth.
"While ibuprofen and similar pain medications are considered adequate for pain control after childbirth, clearly some women need additional help managing pain," said Dr. Zhou. "We need to do a better job identifying who is at risk for postpartum pain and ensure they have adequate postpartum care."
https://www.sciencedaily.com/releases/2018/10/181014142700.htm
Babies of overweight mothers may risk developing self-regulation problems
October 10, 2018
Science Daily/Springer
A mother's weight during early pregnancy may affect how well her baby is able to self-regulate during its first months and years of life. This is according to a study of more than 3100 Finnish women.
Previous research has found that one in every five infants struggles to self-regulate in the first year of life. This means that these babies may cry excessively, have problems feeding or difficulties falling asleep unless soothed by a caregiver. As they grow older, such children often show behavioural and neurodevelopmental problems such as hyperactivity or difficulties concentrating, as well as having poorer muscle function. Some have lower IQs or are placed on the autism spectrum.
The aim of this study was to find out whether a mother's weight during early pregnancy influences her child's neurodevelopment. Girchenko and her colleagues drew on data from 3117 women from different Finnish towns who had given birth between 2006 and 2010. All participants were part of the Prediction and Prevention of Pre-eclampsia and Intrauterine Growth Restriction (PREDO) study.
Medical data was gathered about the mothers' weight during the first few months of their pregnancies, and whether they suffered from high blood pressure or gestational diabetes during this period. Up to three months after delivery, the women then answered questions about their babies' ability to regulate and calm themselves. Follow-up assessments of the children's developmental milestones were conducted between 2011 and 2012.
In general, the participants who were overweight or obese tended to be older mothers and to deliver their babies through a caesarean section. They were also less likely to have a tertiary education and quite often decided to stop smoking when they first heard that they were pregnant.
By the age of 17 days, infants of mothers who were overweight were already found to struggle more often with regulatory behaviour problems. In fact, there was a 22 per cent higher chance that overweight or obese mothers would have children with multiple self-regulatory problems. The research team confirmed that weight was the significant factor, and not whether a mother suffered from high blood pressure or gestational diabetes.
"Our findings show that regulatory behavior problems in infancy have prenatal origins that can be attributed at least partially to mothers being overweight or obesity," explains Girchenko. "We suggest that the prevention of weight problems in women of childbearing age may benefit their later offspring and could reduce the burden of regulatory problems in infancy and prevent their long-term neurodevelopmental consequences."
https://www.sciencedaily.com/releases/2018/10/181010105634.htm
Stress reduces fertility in women
October 1, 2018
Science Daily/Boston University School of Medicine
In North America, 20 to 25 percent of women and 18 to 21 percent of men of reproductive age report daily psychological stress. Although previous research has suggested that stress can decrease the odds of conception, few studies have examined this association among couples from the general population. Now, a new study finds higher levels of stress are associated with lower odds of conception for women, but not for men.
Now, a new study led by Boston University School of Public Health (BUSPH) researchers finds higher levels of stress are associated with lower odds of conception for women, but not for men.
The study was published in the American Journal of Epidemiology.
"Although this study does not definitely prove that stress causes infertility, it does provide evidence supporting the integration of mental health care in preconception guidance and care," says BUSPH doctoral student Amelia Wesselink, the study's lead author.
The researchers used data from the Pregnancy Study Online (PRESTO), an ongoing preconception cohort of North American pregnancy planners that follows couples for 12 months or until pregnancy, whichever comes first. For the new study, the researchers followed 4,769 women and 1,272 men who did not have a history of infertility and had not been trying to conceive for more than six menstrual cycles.
The researchers measured perceived stress using the 10-item version of the perceived stress scale (PSS), which is designed to assess how unpredictable, uncontrollable, and overwhelming an individual finds their life circumstances. The items referred to the past month, with five response choices ranging from 0 (never) to 4 (very often), up to a total of 40, with a higher total score indicating a higher level of perceived stress. Both partners completed the PSS at baseline, and women also completed the PSS at each bi-monthly PRESTO follow-up. The baseline questionnaires also included a range of demographic and behavioral factors, including race/ethnicity, household income, diet, sleep, and frequency of intercourse.
On average, baseline PSS scores were about 1 point higher among women than men, and the average follow-up PSS scores among women remained fairly constant over the 12 months that they participated in the study.
The researchers found women with PSS scores of at least 25 were 13 percent less likely to conceive than women with PSS scores under 10. This association was stronger among women who had been trying to conceive for no more than two menstrual cycles before joining PRESTO than among women who had been trying for three or more cycles before enrolling. The association was also stronger among women under 35 years old.
The researchers found that, if the link between higher levels of stress and lower odds of conception is a causal association, a small proportion of that association could be due to decreased intercourse frequency and increased menstrual cycle irregularity.
The researchers did not find an association between men's PSS score and the likelihood of conceiving. However, couples in the study were about 25 percent less likely to conceive when the man's PSS score was under 10 and the women's was 20 or higher. The authors wrote that this is the first study to suggest that "partner stress discordance" may affect the likelihood of conception, although the finding was imprecise and speculative.
https://www.sciencedaily.com/releases/2018/10/181001171207.htm
Exploring the connection between hearing loss and cognitive decline
Eight-year study reveals association that may indicate early stage changes in cognition
January 29, 2019
Science Daily/Brigham and Women's Hospital
Hearing loss affects tens of millions of Americans and its global prevalence is expected to grow as the world's population ages. A new study led by investigators at Brigham and Women's Hospital adds to a growing body of evidence that hearing loss is associated with higher risk of cognitive decline. These findings suggest that hearing loss may help identify individuals at greater risk of cognitive decline and could provide insights for earlier intervention and prevention.
"Dementia is a substantial public health challenge that continues to grow. There is no cure, and effective treatments to prevent progression or reverse the course of dementia are lacking," said lead author Sharon Curhan, MD, MSc, a physician and epidemiologist in the Channing Division for Network Medicine at the Brigham. "Our findings show that hearing loss is associated with new onset of subjective cognitive concerns which may be indicative of early stage changes in cognition. These findings may help identify individuals at greater risk of cognitive decline."
Curhan and colleagues conducted an eight-year longitudinal study among 10,107 men aged ?62 years in the Health Professionals Follow-up Study (HFPS). They assessed subjective cognitive function (SCF) scores based on responses to a six-item questionnaire administered in 2008, 2012 and 2016. SCF decline was defined as a new report of at least one SCF concern during follow-up.
The team found that hearing loss was associated with higher risk of subjective cognitive decline. Compared with men with no hearing loss, the relative risk of cognitive decline was 30 percent higher among men with mild hearing loss, 42 percent higher among men with moderate hearing loss, and 54 percent higher among men with severe hearing loss but who did not use hearing aids.
Researchers were interested to see if hearing aids might modify risk. Although the found that among men with severe hearing loss who used hearing aids, the risk of cognitive decline was somewhat less (37 percent higher), it was not statistically significantly different from the risk among those who did not use hearing aids. The authors note that this may have been due to limited power or could suggest that if a difference truly exists, the magnitude of the effect may be modest.
The authors also note that the study was limited to predominantly older white male health professionals. This allowed for greater control of variability but further studies in additional populations would be helpful. In addition, the study relies on self-reported hearing loss and subjective measures of cognitive function. In the future, the team plans to investigate the relationships between self-reported hearing loss, change in audiometric hearing thresholds, and changes in cognition in women using several different assessment measures.
"Whether there is a temporal association between hearing loss and cognitive decline and whether this relation is causal remains unclear," said Curhan. "We plan to conduct further longitudinal studies of the relation of hearing loss and cognition in women and in younger populations, which will be informative."
https://www.sciencedaily.com/releases/2019/01/190129081936.htm
Poor sleep at night, more pain the next day
January 29, 2019
Science Daily/Society for Neuroscience
After one night of inadequate sleep, brain activity ramps up in pain-sensing regions while activity is scaled back in areas responsible for modulating how we perceive painful stimuli. This finding provides the first brain-based explanation for the well-established relationship between sleep and pain.
In two studies -- one in a sleep laboratory and the other online -- Matthew Walker and colleagues show how the brain processes pain differently when individuals are sleep deprived and how self-reported sleep quality and pain sensitivity can change night-to-night and day-to-day. When the researchers kept healthy young adults awake through the night in the lab, they observed increased activity in the primary somatosensory cortex and reduced activity in regions of the striatum and insula cortex during a pain sensitivity task. Participants in the online study, recruited via the crowdsourcing marketplace Amazon Mechanical Turk, reported increased pain during the day after reporting poor sleep the night before.
These results suggest improving sleep quality, especially in hospital settings, could be an effective approach for pain management. More generally, the research highlights the interrelationship between sleep and pain, which is decreasing and increasing, respectively, in societies around the world.
https://www.sciencedaily.com/releases/2019/01/190129093714.htm
Lowering blood pressure reduces risk of cognitive impairment
January 28, 2019
Science Daily/Wake Forest Baptist Medical Center
Intensive control of blood pressure in older people significantly reduced the risk of developing mild cognitive impairment (MCI), a precursor of early dementia, in a clinical trial led by scientists at Wake Forest School of Medicine, part of Wake Forest Baptist Health. However, the National Institutes of Health-supported Systolic Blood Pressure Intervention Trial (SPRINT) Memory and Cognition in Decreased Hypertension (SPRINT MIND) study did not prove that treating blood pressure to a goal of 120 mm Hg or less statistically reduced the risk of dementia. This result may have been due to too few new cases of dementia occurring in the study, the authors noted.
The results were reported in the Jan. 28 edition of the Journal of the American Medical Association.
MCI is defined as a decline in memory and thinking skills that is greater than expected with normal aging and is a risk factor for dementia. Dementia is defined as a group of symptoms associated with a decline in memory or other thinking skills severe enough to reduce a person's ability to perform everyday activities.
"As doctors treating older patients, we are encouraged to finally have a proven intervention to lower someone's risk for MCI," said the study's principal investigator, Jeff Williamson, M.D., professor of gerontology and geriatric medicine at Wake Forest School of Medicine. "In the study, we found that just three years of lowering blood pressure not only dramatically helped the heart but also helped the brain."
The objective of SPRINT MIND was to evaluate the effect of intensive blood pressure control on risk of dementia. Hypertension, which affects more than half of people over age 50 and more than 75 percent of those older than 65, has been identified as a potentially modifiable risk factor for MCI and dementia in previous observational studies.
The clinical trial, which enrolled 9361 volunteers, was conducted at 102 sites in the United States and Puerto Rico among adults 50 and older with hypertension but without diabetes or history of stroke. The participating group was 35.6 percent female, 30 percent black and 10.5 percent Hispanic and thus representative of the broader U.S. population.
Participants were randomly assigned to a systolic blood pressure goal of either less than 120 mm HG (intensive treatment) or less than 140 mm HG (standard treatment). They were then classified after five years as having no cognitive impairment, MCI or probable dementia.
"Although the study showed a 15 percent reduction in dementia in the intensively controlled group, we were disappointed that the results did not achieve statistical significance for this outcome," Williamson said. "Last week the Alzheimer's Association agreed to fund additional follow-up of SPRINT MIND participants in the hope that sufficient dementia cases will accrue, allowing for a more definitive statement on these outcomes."
SPRINT was stopped early due to the success of the trial in reducing cardiovascular disease. As a result, participants were on intensive blood pressure lowering treatment for a shorter period than originally planned. The authors concluded that the shorter time may have made it difficult to accurately determine the role of intensive blood pressure control on dementia cases.
Williamson said some caution should be exercised in interpreting the study result both because MCI was not the primary cognitive focus of the trial and because it is not clear what intensive blood pressure control may mean for the longer-term incidence of dementia. Although MCI considerably increases the risk of dementia, this progression is not inevitable and reversion to normal cognition is possible, he said.
https://www.sciencedaily.com/releases/2019/01/190128111703.htm
Gut bacteria may control movement
Study suggests that bacteria may regulate neuronal circuits behind movement in flies
November 1, 2018
Science Daily/NIH/National Institute of Neurological Disorders and Stroke
A new study puts a fresh spin on what it means to 'go with your gut.' The findings suggest that gut bacteria may control movement in fruit flies and identify the neurons involved in this response.
"This study provides additional evidence for a connection between the gut and the brain, and in particular outlines how gut bacteria may influence behavior, including movement," said Margaret Sutherland, Ph.D., program director at NINDS.
Researchers led by Sarkis K. Mazmanian, Ph.D., professor of microbiology at the California Institute of Technology in Pasadena, and graduate student Catherine E. Schretter, observed that germ-free flies, which did not carry bacteria, were hyperactive. For instance, they walked faster, over greater distances, and took shorter rests than flies that had normal levels of microbes. Dr. Mazmanian and his team investigated ways in which gut bacteria may affect behavior in fruit flies.
"Locomotion is important for a number of activities such as mating and searching for food. It turns out that gut bacteria may be critical for fundamental behaviors in animals," said Dr. Mazmanian.
Fruit flies carry between five and 20 different species of bacteria and Dr. Mazmanian's team treated the germ-free animals with individual strains of those microbes. When the flies received Lactobacillus brevis, their movements slowed down to normal speed. L. brevis was one of only two species of bacteria that restored normal behavior in the germ-free flies.
Dr. Mazmanian's group also discovered that the molecule xylose isomerase (Xi), a protein that breaks down sugar and is found in L. brevis, may be critical to this process. Isolating the molecule and treating germ-free flies with it was sufficient to slow down the speedwalkers.
Additional experiments showed that Xi may regulate movement by fine-tuning levels of certain carbohydrates, such as trehalose, which is the main sugar found in flies and is similar to mammalian glucose. Flies that were given Xi had lower levels of trehalose than did untreated germ-free flies. When Xi-treated flies, which showed normal behavior, were given trehalose alone, they resumed fast movements suggesting that the sugar was able to reverse the effects of Xi.
Next, the researchers looked into the flies' nervous system to see what cells were involved in bacteria-directed movement. When Dr. Mazmanian's team turned on neurons that produce the chemical octopamine, that activation canceled out the effect of L. brevis on the germ-free flies. As a result, the flies, which had previously slowed down after receiving the bacterium or Xi, resumed their speedwalking behavior. Turning on octopamine-producing nerve cells in flies with normal levels of bacteria also caused them to move faster. However, activating neurons that produce other brain chemicals did not influence the flies' movements.
According to Dr. Mazmanian, Schretter and their colleagues, Xi may be monitoring the flies' metabolic state, including levels of nutrients, and then signaling to octopamine neurons whether they should turn on or off, resulting in changes in behavior.
Instead of octopamine, mammals produce a comparable chemical called noradrenaline, which has been shown to control movement.
"Gut bacteria may play a similar role in mammalian locomotion, and even in movement disorders such as Parkinson's disease," said Dr. Mazmanian.
More research is needed to see whether bacteria control movement in other species, including mammals. In addition, future studies will further investigate how Xi is involved in these behaviors.
https://www.sciencedaily.com/releases/2018/11/181101085302.htm
Inflammation can lead to circadian sleep disorders
Novel technology turns inflammation on and off, affecting body clock in mice
October 31, 2018
Science Daily/Northwestern University
Inflammation, which is the root cause of autoimmune disorders including arthritis, type 1 diabetes, irritable bowel syndrome and Crohn's disease, has unexpected effects on body clock function and can lead to sleep and shiftwork-type disorders, a new study in mice found.
The study was published in the journal Genes & Development.
The study used a new technology -- a genetic switch -- to turn inflammation on and off in genetically modified mouse models. When researchers deactivated inflammation, the mouse was unable to tell what time it was and was unable to keep an intact rest-activity cycle.
In addition to this new technology, the study was novel because, for the first time, scientists saw a link between what causes inflammation and what controls the body's clock.
In inflammatory diseases, the body experiences an excess of a genetic factor known as NF-kappa beta (NFKB), the study found. NFKB is a catalyst for a set of chain reactions, or pathway, that leads to the pain and tissue destruction patients feel in inflammatory diseases. That same chain-reaction catalyst also controls the body's clock.
"NFKB alters the core processor through which we tell time, and now we know that it is also critical in linking inflammation to rest-activity patterns," said senior author Dr. Joseph Bass, the Charles F. Kettering Professor of Medicine and director of the Center for Diabetes and Metabolism at Northwestern University Feinberg School of Medicine.
When people have sore muscles and take an ibuprofen to reduce the inflammation, they are essentially trying to turn down the activation of inflammation, which is similar to what the authors did in this study, Bass said.
The findings also have implications for diet and provide a detailed roadmap to understanding the fundamental mechanisms by which inflammation -- including the inflammation that occurs when someone chronically consumes a high-fat diet -- and likely other instigators lead to circadian disorders.
The scientists sought to understand how a high-fat diet might affect the perception of time at the tissue level, which is what led to their study of inflammation, said first author Hee-Kyung Hong, research assistant professor of endocrinology at Feinberg.
One of the reasons Western diet contributes to diabetes, cardiovascular disease and even certain cancers is thought to be the inappropriate trigger of inflammation, so a unifying idea is that impaired time-keeping may be one of the links between diet and disease.
"We don't know the reasons, but this interaction between the inflammation and clocks is not only relevant to understanding how inflammation affects the brain and sleep-wake cycle but also how immune or fat cells work," Hong said.
https://www.sciencedaily.com/releases/2018/10/181031124858.htm
Three types of depression identified
October 31, 2018
Science Daily/Okinawa Institute of Science and Technology (OIST) Graduate University
Scientists have used brain imaging to identify three sub-types of depression -- including one that is unresponsive to commonly prescribed serotonin boosting drugs.
According to the World Health Organization, nearly 300 million people worldwide suffer from depression and these rates are on the rise. Yet, doctors and scientists have a poor understanding of what causes this debilitating condition and for some who experience it, medicines don't help.
Scientists from the Neural Computational Unit at the Okinawa Institute of Science and Technology Graduate University (OIST), in collaboration with their colleagues at Nara Institute of Science and Technology and clinicians at Hiroshima University, have for the first time identified three sub-types of depression. They found that one out of these sub-types seems to be untreatable by Selective Serotonin Reuptake Inhibitors (SSRIs), the most commonly prescribed medicines for the condition. The study was published in the journal Scientific Reports.
Serotonin is a neurotransmitter that influences our moods, interactions with other people, sleep patterns and memory. SSRIs are thought to take effect by boosting the levels of serotonin in the brain. However, these drugs do not have the same effect on everyone, and in some people, depression does not improve even after taking them. "It has always been speculated that different types of depression exist, and they influence the effectiveness of the drug. But there has been no consensus," says Prof. Kenji Doya.
For the study, the scientists collected clinical, biological, and life history data from 134 individuals -- half of whom were newly diagnosed with depression and the other half who had no depression diagnosis- using questionnaires and blood tests. Participants were asked about their sleep patterns, whether or not they had stressful issues, or other mental health conditions.
Researchers also scanned participants' brains using magnetic resonance imaging (MRI) to map brain activity patterns in different regions. The technique they used allowed them to examine 78 regions covering the entire brain, to identify how its activities in different regions are correlated. "This is the first study to identify depression sub-types from life history and MRI data," says Prof. Doya.
With over 3000 measurable features, including whether or not participants had experienced trauma, the scientists were faced with the dilemma of finding a way to analyze such a large data set accurately. "The major challenge in this study was to develop a statistical tool that could extract relevant information for clustering similar subjects together," says Dr. Tomoki Tokuda, a statistician and the lead author of the study. He therefore designed a novel statistical method that would help detect multiple ways of data clustering and the features responsible for it. Using this method, the researchers identified a group of closely-placed data clusters, which consisted of measurable features essential for accessing mental health of an individual. Three out of the five data clusters were found to represent different sub-types of depression.
The three distinct sub-types of depression were characterized by two main factors: functional connectivity patterns synchronized between different regions of the brain and childhood trauma experience. They found that the brain's functional connectivity in regions that involved the angular gyrus -- a brain region associated with processing language and numbers, spatial cognition, attention, and other aspects of cognition -- played a large role in determining whether SSRIs were effective in treating depression.
Patients with increased functional connectivity between the brain's different regions who had also experienced childhood trauma had a sub-type of depression that is unresponsive to treatment by SSRIs drugs, the researchers found. On the other hand, the other two subtypes -- where the participants' brains did not show increased connectivity among its different regions or where participants had not experienced childhood trauma -- tended to respond positively to treatments using SSRIs drugs.
This study not only identifies sub-types of depression for the first time, but also identifies some underlying factors and points to the need to explore new treatment techniques. "It provides scientists studying neurobiological aspects of depression a promising direction in which to pursue their research," says Prof. Doya. In time, he and his research team hope that these results will help psychiatrists and therapists improve diagnoses and treat their patients more effectively.
https://www.sciencedaily.com/releases/2018/10/181031093337.htm