Nutrition protects against the impact of stress on the brain in early life
November 14, 2016
Science Daily/Universiteit van Amsterdam (UVA)
Young mice that grow up in stressful circumstances go on to have fewer cognitive-impairments and memory problems as adults if they are given enriched breast milk, scientists report.
In both humans and other animals, severe stress in early childhood (human examples are abuse and neglect or war trauma) results in impaired brain development and health issues later in life. For example, people exposed to early-life stress have a higher risk of developing depression, anxiety disorders and other diseases such as obesity, and on average have a lower IQ and a less effective memory.
Long-term hospital stay
Previous research conducted by neuroscientists Eva Naninck, Paul Lucassen and Aniko Korosi revealed that stress during early development also permanently changes the brain in mice. This current study conducted by the same group demonstrates that supplementing the nutrition of the mother during this early period can mitigate the harmful consequences of this early-life stress later on. Korosi: 'The fact that nutrients can influence impaired brain development deriving from stress in early childhood is hopeful. It enables us to look in a targeted way for nutritional interventions for children who are growing up in stressful circumstances, for example babies that have to undergo long-term hospital stays.'
To induce stress in young mice, the researchers gave mother mice only a limited amount of material with which to build their nests. As a result, their care for their young changed, and they left the nest more often in order to look for nesting material. Mothers in the control group who had plenty of nesting material at their disposal, on the other hand, stayed in the nest with their young for much longer periods of time.
The researchers gave half of the stressed mother mice a dietary supplement containing various nutrients which the body is unable to produce on its own, such as vitamins B6, B9 (folic acid) and B12 and the functionally related aminoacid, methionine.
The researchers found an increased hormonal stress response and reduced methionine levels in the brains of those young mice whose mothers were stressed, but were not given the nutritional supplement. In addition, these mice had an impaired memory as adults; they were less able to remember locations and objects.
The young of stressed mothers that were given supplemented nutrition were more similar to conspecifics growing up under normal circumstances. They had higher methionine levels in the brain and a lower hormonal stress response when young, and as adults they performed better on several memory tasks than the early-stress exposed mice whose mothers did not receive a nutritional supplement.
Human breast milk
The researchers emphasise that this explorative study was unable to fully explain precisely how the stress system and metabolism work together in this early period and in brain development. It is unclear whether the impaired development is due to the fact that stress-exposed mothers produce less nutritious milk, or if the problem lies with absorption in the body or brain of the young mice, who may also experience stress as result of the mother's unpredictable behaviour. However, according to Naninck the results are still valuable: 'Scientists tend to view metabolism and stress as unrelated systems, but we have demonstrated that in fact they work together in early brain programming. We hope that our insights can contribute to new nutrition strategies to mitigate the lasting effects of a seriously disturbed childhood.'
Before this kind of nutritional intervention can be used in people, it first has to be established whether human mothers and babies under serious stress, experience similar disturbances to mice. Currently, the group's first step is to investigate whether the nutritional content of human breast milk also changes under stress.
https://www.sciencedaily.com/releases/2016/11/161114082239.htm
New survey finds 75 percent of Americans think discrimination still an issue for women
Only three in 10 consider Hillary Clinton's gender to be a significant obstacle for her campaign
August 31, 2016
Science Daily/NORC at the University of Chicago
In the wake of Hillary Clinton's historic nomination as the first woman presidential candidate of a major political party in the US, women continue to face obstacles in politics and the workplace, according to an American national poll. Three-quarters of Americans think there is at least some discrimination against women in this country, although just as many say it has decreased over the past generation.
"The impact of the country's first female nominee is perceived differently across the electorate including how Clinton's gender will impact her chances of being elected and what the long-term effects will be on gender discrimination," said Trevor Tompson, director of The AP-NORC Center. "For example, women and men are divided in their perception of the role gender will play in the outcome. Women are more inclined to say that Clinton's gender is a disadvantage, while men tend to say the fact that she is a woman will help her chances of being elected."
Some of the poll's key findings are:
- · Seventy-five percent say women and men are equally good at being political leaders. Yet, 53 percent think women have fewer opportunities in politics than men.
- · The public is divided on whether Clinton's gender is an advantage, a hindrance or neither for her election prospects this fall. Men are more inclined to say her gender is a benefit to her campaign, and women are more likely to say it is a barrier.
- · Seven in 10 say the historic nature of Clinton's candidacy has no bearing on their own vote choice this year. Nearly 20 percent say the opportunity to elect the first woman president makes them more inclined to vote for Clinton in November, and about 10 percent say it makes them less likely to vote for her.
- · Overall, 75 percent think discrimination against women has decreased over the past 25 years or so, but at the same time an equal number of Americans say discrimination continues to be an issue today for many women.
- · Forty-nine percent of the public think it would help the economy if the upper management of companies were made up of equal numbers of men and women. Just 2 percent say it would be bad for the economy, while 48 percent think it would make no difference.
- · However, just 4 percent of Fortune 500 CEOs are women and the workplace is perceived as an uneven playing field for women. More than half of Americans think women have fewer opportunities for job advancement and 6 in 10 say they are at a disadvantage when it comes to salaries.
- · In fact, just under half of the women surveyed said they had experienced at least some type of job-related discrimination -- getting a job, receiving equal pay, or being appreciated and promoted at work -- because of their gender. Three in 10 men report having been discriminated against in some way at work because of their gender.
- · Six in 10 do not expect a Clinton Administration to have any effect on the level of discrimination against women, while a quarter anticipate a reduction in the amount of discrimination women would face if Clinton is elected.
https://www.sciencedaily.com/releases/2016/08/160831223832.htm
Mental stress may cause reduced blood flow in hearts of young women with heart disease
August 24, 2016
Science Daily/American Heart Association
Mental stress may cause reduced blood flow in the heart muscle of younger women with heart disease. Younger women with heart disease are more susceptible to reduced blood flow from mental stress compared to men and older patients, new research has found.
Younger women with coronary heart disease and mental stress are more susceptible to myocardial ischemia (reduced blood flow to the heart muscle, which can lead to a heart attack), compared to men and older patients, according to new research in Journal of the American Heart Association, the Open Access Journal of the American Heart Association/American Stroke Association.
Coronary heart disease is a leading cause of death in American men and women, but studies show that younger women have higher rates of complications and death after a heart attack compared to their male counterparts.
"Younger women tend to have quite a lot of stress in their lives. Many of them have full-time jobs and at the same time have numerous responsibilities at home; financial hardship, as well as depression and anxiety which are common in this group," said Viola Vaccarino, M.D., Ph.D., lead study author, professor and chair of the department of epidemiology at Emory University in Atlanta, Georgia. "Clinicians should ask about stress and emotional difficulties in these patients and recommend ways to help, such as finding time to relax and exercise."
The Mental Stress Ischemia Mechanisms Prognosis study included 686 patients (191 women) between 34 and 79 years old with coronary heart disease. Patients underwent imaging tests, meaning researchers took pictures of their hearts before and during mental stress, and then examined changes in blood flow between men and women with age as a factor.
They found stress-induced, reduced blood flow:
· happened more often in younger women compared to men and older women;
· occurred in 33 percent of women age 50 years old or younger compared to 8 percent of men of similar ages; and
· the difference between men and women decreased with age and disappeared in older patients. The frequency of reduced blood flow almost doubled in women compared to men for every 10-year decrease in age.
"Our findings suggest that women with heart disease in their 30s, 40s and early 50s are more vulnerable to the damaging effects of psychological stress on their heart," Vaccarino said.
Researchers said their study is limited by the relatively small number of younger women involved and that further studies are needed to confirm the clinical significance of mental stress-induced heart attacks in women.
https://www.sciencedaily.com/releases/2016/08/160824171748.htm
Unhealthy diet during pregnancy could be linked to ADHD
August 18, 2016
Science Daily/King's College London
A high-fat, high-sugar diet during pregnancy may be linked to symptoms of ADHD in children who show conduct problems early in life, new research indicates.
Published in the Journal of Child Psychology and Psychiatry, this study is the first to indicate that epigenetic changes evident at birth may explain the link between unhealthy diet, conduct problems and ADHD.
Early onset conduct problems (e.g. lying, fighting) and attention-deficit/hyperactivity disorder (ADHD) are the leading causes of child mental health referral in the UK. These two disorders tend to occur in tandem (more than 40 per cent of children with a diagnosis of conduct disorder also have a diagnosis of ADHD) and can also be traced back to very similar prenatal experiences such as maternal distress or poor nutrition.
In this new study of participants from the Bristol-based 'Children of the 90s' cohort, 83 children with early-onset conduct problems were compared with 81 children who had low levels of conduct problems. The researchers assessed how the mothers' nutrition affected epigenetic changes (or DNA methylation) of IGF2, a gene involved in fetal development and the brain development of areas implicated in ADHD -- the cerebellum and hippocampus. Notably, DNA methylation of IGF2 had previously been found in children of mothers who were exposed to famine in the Netherlands during World War II.
The researchers from King's and Bristol found that poor prenatal nutrition, comprising high fat and sugar diets of processed food and confectionary, was associated with higher IGF2 methylation in children with early onset conduct problems and those with low conduct problems.
Higher IGF2 methylation was also associated with higher ADHD symptoms between the ages of 7 and 13, but only for children who showed an early onset of conduct problems.
Dr Edward Barker from King's College London said: 'Our finding that poor prenatal nutrition was associated with higher IGF2 methylation highlights the critical importance of a healthy diet during pregnancy.
'These results suggest that promoting a healthy prenatal diet may ultimately lower ADHD symptoms and conduct problems in children. This is encouraging given that nutritional and epigenetic risk factors can be altered.'
Dr Barker added: 'We now need to examine more specific types of nutrition. For example, the types of fats such as omega 3 fatty acids, from fish, walnuts and chicken are extremely important for neural development.
'We already know that nutritional supplements for children can lead to lower ADHD and conduct problems, so it will be important for future research to examine the role of epigenetic changes in this process.'
https://www.sciencedaily.com/releases/2016/08/160818085803.htm
Calcium supplements linked to dementia risk in women with certain health conditions
August 17, 2016
Science Daily/American Academy of Neurology
Calcium supplements may be associated with an increased risk of dementia in older women who have had a stroke or other signs of cerebrovascular disease, according to a new study.
Cerebrovascular disease is a group of disorders that affect blood flow in the brain. These diseases, including stroke, are the fifth leading cause of death in the United States and increase the risk of developing dementia.
"Osteoporosis is a common problem in the elderly. Because calcium deficiency contributes to osteoporosis, daily calcium intake of 1000 to 1200 mg is recommended. Getting this recommended amount through diet alone can be difficult, so calcium supplements are widely used," said study author Silke Kern, MD, PhD with the University of Gothenburg in Sweden. "Recently, however, the use of supplements and their effect on health has been questioned."
The study involved 700 dementia-free women between the ages of 70 and 92 who were followed for five years. Participants took a variety of tests at the beginning and end of the study, including tests of memory and thinking skills. A CT brain scan was performed in 447 participants at the start of the study.
Scientists also looked at the use of calcium supplements in the participants and whether they were diagnosed with dementia over the course of the study. A total of 98 women were taking calcium supplements at the start of the study and 54 women had already experienced a stroke. During the study, 54 more women had strokes, and 59 women developed dementia. Among the women who had CT scans, 71 percent had lesions on their brains' white matter, which is a marker for cerebrovascular disease.
The study found that the women who were treated with calcium supplements were twice as likely to develop dementia than women who did not take supplements. But when the researchers further analyzed the data, they found that the increased risk was only among women with cerebrovascular disease. Women with a history of stroke who took supplements had a nearly seven times increased risk of developing dementia than women with a history of stroke who did not take calcium supplements. Women with white matter lesions who took supplements were three times as likely to develop dementia as women who had white matter lesions and did not take supplements. Women without a history of stroke or women without white matter lesions had no increased risk when taking calcium supplements.
Overall, 14 out of 98 women who took supplements developed dementia, or 14 percent, compared to 45 out of 602 women who did not take supplements, or 8 percent. A total of six out of 15 women with a history of stroke who took supplements developed dementia, compared to 12 out of 93 women with a history of stroke who did not take supplements. Among the women with no history of stroke, 18 out of 83 who took supplements developed dementia, compared to 33 out of the 509 who did not take supplements.
"It is important to note that our study is observational, so we cannot assume that calcium supplements cause dementia," said Kern. The author also noted that the study was small and results cannot be generalized to the overall population, and additional studies are needed to confirm the findings.
Kern noted that calcium from food affects the body differently than calcium from supplements and appears to be safe or even protective against vascular problems.
https://www.sciencedaily.com/releases/2016/08/160817171555.htm
One third of women with ADHD have anxiety disorders, almost half have considered suicide
July 20, 2016
Science Daily/University of Toronto
Women with ADHD are much more likely to have a wide range of mental and physical health problems in comparison to women without ADHD, according to a new study.
"The prevalence of mental illness among women with ADHD was disturbingly high with 46% having seriously considered suicide, 36% having generalized anxiety disorder, 31% having major depressive disorder and 39% having substance abuse problems at some point in their life," reported Esme Fuller-Thomson, Sandra Rotman Endowed Chair at University of Toronto's Factor-Inwentash Faculty of Social Work and Director of the Institute for Life Course & Aging.
"These rates are much higher than among women without ADHD, ranging from more than four times the odds of suicidal thoughts and generalized anxiety disorders to more than twice the odds of major depressive disorder and substance abuse" said Fuller-Thomson
Investigators examined a representative sample of 3,908 Canadian women aged 20 to 39 of whom 107 reported that they had been diagnosed with ADHD. Data was drawn from the 2012 Canadian Community Health Survey-Mental Health.
"We were surprised at the high levels of physical health problems that the women were experiencing" said Danielle A. Lewis, co-author of the study and a recent MSW graduate of the University of Toronto.
"More than one in four (28%) of these relatively young women said that physical pain prohibited some of their activities, which was much higher than the 9% of their peers without ADHD who had disabling pain. Insomnia was also more prevalent in the women with ADHD in comparison to those without ADHD (43.9% vs 12.2%) as was smoking (41% vs 22%)" stated Lewis.
"Unfortunately, our study does not provide insight into why women with ADHD are so vulnerable. It is possible that some of the mental health problems may be caused by and/or contributing to financial stress" Fuller-Thomson suggested. The study also found, one in three of the women (37%) with ADHD reported they had difficulty meeting basic expenses such as food, shelter and clothing due to their inadequate household income. For women without ADHD, only 13% had this shortfall."
"Many people think of ADHD as primarily a boys' disorder which has little relevance for girls and women. Our findings suggest, to the contrary, that a large portion of women with ADHD are struggling with mental illness, physical health concerns and poverty," said Fuller-Thomson.
"In light of these problems, it is important that primary health care providers are particularly vigilant in monitoring and treating their female patients with ADHD," suggested co-author Senyo Agbeyaka, a graduate student at the University of Toronto.
https://www.sciencedaily.com/releases/2016/07/160720122838.htm
New evidence links exclusive breastfeeding, early play/stimulation to children's later success
Enriched play/stimulation to age two creates brighter four-year-olds, say investigators
June 21, 2016
Science Daily/Grand Challenges Canada
A pair of new studies further strengthen scientific understanding of the links between what a child experiences in the first years of life and later childhood behavior and abilities. Researchers working in South Africa and Pakistan report their findings in a new paper.
Funded by the Government of Canada through Grand Challenges Canada, researchers working in South Africa and Pakistan report their findings in papers launched today.
In the first study, an international team led by Dr Ruth M. Bland of the Royal Hospital for Sick Children and Institute of Health and Wellbeing, University of Glasgow, assessed over 1,500 children in South Africa, 900 of whom had been involved in an early infant feeding study.
They found longer durations of exclusive breastfeeding strongly associated with fewer conduct disorders at ages 7 to 11 years. Children exclusively breastfed for the recommended six months, compared with those exclusively breastfed for less than one month, were approximately half (56 percent) as likely to have conduct disorders at primary school age.
Other highlighted findings, published in PLOS Medicine, included:
- · Important determinants of a child's cognitive development: attending creche (preschool) and mother's IQ
- · Children who attended creche for at least one year were 74 percent more likely to have higher executive function (which enables us to plan, focus attention, remember instructions, and juggle multiple tasks successfully. The brain needs this skill set to filter distractions, prioritize tasks, set and achieve goals, and control impulses. Executive function, therefore, influences educational and social success.)
- · Children stimulated at home, such as through play, were one third (36 percent) more likely to have higher executive function scores
- · There was weaker evidence that, for boys, exclusive breastfeeding for more than one month improved cognitive development.
The study also examined a number of current life factors that might influence children's development, finding that children were two-and-a-half times more likely to exhibit emotional-behavioural problems if their mothers had a current mental health problem or severe parenting stress.
"The duration of exclusive breastfeeding of an infant has greater importance than previously realized in several areas of development," said lead author Dr Tamsen J. Rochat of the Human Science Research Council, Durban, South Africa.
"For example, childhood onset conduct disorders can lead to aggressive or disruptive behaviours, which interfere with learning and peer relationships, in turn leading to low self-esteem and further behavioural problems. Conduct disorders that start in childhood and persist into the teen years are associated with an increase in antisocial (and potentially violent or criminal) behaviours, poor long-term mental health and low academic achievement in later life."
"Evidence from studies in high-income countries suggests that the economic cost of conduct disorders is enormous," added Dr Bland. For example, a publication from the United Kingdom cited in the paper estimates the annual cost of crime attributable to people who had a conduct disorder in childhood at US$117 billion.
The study was also one of the first to assess the impact of HIV exposure on the development of primary school-age children in Africa. Previous studies suggested that children, although themselves HIV-negative, were disadvantaged if they were born to HIV-positive mothers, particularly in the areas of emotional and behavioural development. This study found that HIV-negative children born to HIV-positive mothers performed as well as those born to HIV-negative mothers.
Play and communication -- "responsive stimulation" -- pays dividends for impoverished rural children in Pakistan
The second paper, published by The Lancet Global Health and led by Dr Aisha K. Yousafzai of Aga Khan University, Karachi, followed up a cohort of impoverished children in rural Pakistan whose parents had been guided on strengthening nutritional care and "responsive stimulation" used to the end of age 2.
In the responsive stimulation intervention, caregivers were coached to observe and respond to their child's cues during play and communication activities, improving the quality of interactions.
The intervention, adapted from the UNICEF and the World Health Organization's 'Care for Child Development' approach (which is readily available online), included using everyday household items or homemade toys to stimulate children's cognitive, language, motor and affective (emotional/feeling) skills.
At age 4, children who received the responsive stimulation intervention were, to varying degrees, more likely to have:
· Higher IQ
· Better pre-academic skills (in sizes and comparisons, and shapes)
· Better executive functioning
· More pro-social behaviour.
The follow-up study also found parents were better caregivers.
The research involved 1,302 four-year-olds and their mothers from the original study, which had likewise shown that responsive stimulation "significantly benefitted children's cognitive, language and motor development at two years." The investigators intend to follow this cohort throughout their schooling.
"The abilities fostered by stimulation are important for readiness and a successful transition to preschool," said Dr Yousafzai. "The competencies assessed in this study have been shown to predict school engagement and longer-term academic attainment."
"Other studies have shown that the early success of children clearly links to their productivity and income potential later in life and, at a large scale, impacts the economic well-being of societies."
The inclusion of stimulation intervention in health programs is important to support healthy development. It is hoped more research will follow that will provide insights on how to optimize integrated packages of health, growth and development.
The newly published research from South Africa and Pakistan closely follows the release of another Grand Challenges Canada study, conducted by Harvard University, showing that one-third of 3- or 4-year-olds in low- and middle-income countries don't reach expected developmental milestones.
Grand Challenges Canada funded the studies as part of its contribution to the growing international "Saving Brains" partnership, which convenes for a conference in Toronto June 21-22, focused on the results from 11 follow-up studies, including the two publications launched today.
"One in three children in 'developing' countries are in fact failing to develop to their full potential. These studies show how parents can help develop smart, social kids who make good decisions: breastfeed babies and play with children," said Dr Peter A. Singer, Chief Executive Officer of Grand Challenges Canada.
https://www.sciencedaily.com/releases/2016/06/160621193106.htm
Postpartum depression least severe form of depression in mothers
Time frame when pregnant woman first develops depression determines severity, treatment of it
June 15, 2016
Science Daily/Northwestern University
Postpartum depression -- a household term since actress Brooke Shields went public in 2005 about her struggle with it -- is indeed serious. But depression that begins before or during pregnancy is often more severe because it lasts longer and usually goes undetected until the doctor screens for it after the birth of the baby, according to a new study.
Deciphering the onset time can impact how the doctor treats the woman's depression, such as intervening earlier with psychiatric help, if needed, said Sheehan Fisher, the study's corresponding author and an instructor of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine.
"There's a difference between postpartum depression and depression that started before or during the pregnancy. It's not a homogenous disorder, " Fisher said. "When clinicians see a mother during the postpartum period and diagnose her with depression, it's important for them to ask how long this depression has been an issue so they can assess the longevity and severity."
The study, recently published in the Journal of Affective Disorders, is one of the first to evaluate the rate of depression in mothers at the three onset time points: 24.9 percent of participants developed depression pre-pregnancy, 36.7 percent developed it during pregnancy (prenatal) and 38.4 percent developed depression during the postpartum period.
Mothers who develop depression during the postpartum period are more likely to be Caucasian, older, educated, married or cohabitating, and have private health insurance than mothers whose depression begins before or during pregnancy, the study found.
"Mothers who develop postpartum depression often experience protective risk factors such as better access to resources, fewer children and are more mature, which helps them adapt to the stress of pregnancy," Fisher said. "Once their babies are born, they show more obsessive-compulsive symptoms--like over-worrying about their baby's health--than mothers who developed depression before or during pregnancy."
Women who had depression before they became pregnant were more likely to experience hypersomnia or difficulty falling asleep. They also experienced more symptoms of paranoia, such as a psychotic episode, than women who developed depression during or after pregnancy. And they had a higher severity of postpartum depression than the other onset periods.
The proportion of mothers who had a bipolar disorder, which Fisher said is more severe than unipolar depression, was significantly higher among mothers whose depression onset was during the pre-pregnancy period (38.7 percent), compared with prenatal (22.6 percent) and postpartum (17.9 percent).
Agitation was the distinctive factor that differentiated mothers with unipolar and bipolar depression in the study. Mothers who had a bipolar disorder and developed depression during her pregnancy exhibited the highest amount of agitation.
The study evaluated depression symptoms during the four- to six-week postpartum period for 727 women from an urban women's hospital in Pittsburgh, Penn. This period was chosen because women typically visit their doctors for post-birth evaluations six weeks after birth, and the four- to six-week epoch is associated with the highest depression onset.
https://www.sciencedaily.com/releases/2016/06/160615142624.htm
Stress exposure during pregnancy observed in mothers of children with autism
More research needed to understand gene-stress interaction
June 7, 2016
Science Daily/University of Missouri-Columbia
Stress during pregnancy has been linked to several conditions, including some instances of autism spectrum disorder. Now, researchers have observed a variant of a stress-sensitive gene and exposure to stress during pregnancy among two groups of mothers of children with autism. The finding could be a step toward helping identify women who have greater risks for having children with autism when exposed to stressors during pregnancy.
"Autism was thought to be largely a genetic disorder, but previous research has shown that environmental influences such as stress can play an important role in the development of the condition," said David Beversdorf, M.D., associate professor in the departments of radiology, neurology and psychological sciences at the University of Missouri and the MU Thompson Center for Autism and Neurodevelopmental Disorders, and senior author of the study. "We know that some mothers who experience significant levels of stress don't have children with autism, but others do. To help understand why, we studied a gene that is known to affect stress and found a link between it and the development of autism with exposure to stress."
Led by Beversdorf's graduate student, Patrick Hecht, Ph.D., in collaboration with Xudong Liu, Ph.D., with Queen's University in Ontario, Canada, the researchers studied two separate groups of mothers of children with autism spectrum disorder -- a group of families at MU and a group of families at Queen's University. The mothers were surveyed about stress during their pregnancy, such as loss of a job, moving or divorce. The mothers' blood was tested for a variation of the stress-sensitive gene known as 5-HTTLPR, which regulates the neurotransmitter serotonin in the nervous system. When a variation of the gene is present, the availability of serotonin is altered, causing an increased reaction to stress.
In both groups, mothers of children with autism who have the variation of the stress-sensitive gene reported experiencing more stress during the end of the second and the beginning of the third trimester of pregnancy, compared to mothers who did not carry the altered gene.
"Though this was an observational study and future confirmation of this finding is needed, it's possible we could, one day, identify women who may be at a greater risk of having a child with autism when exposed to stress," said Beversdorf, who also serves as the William and Nancy Thompson Endowed Chair in Radiology. "More research is needed to understand the mechanisms of how this gene-stress interaction works, but hopefully this could someday help prevent some cases of autism."
https://www.sciencedaily.com/releases/2016/06/160607220116.htm
Prenatal stress could enhance protective mechanisms of babies
May 13, 2016
Science Daily/Universität Basel
Maternal stress and depression during pregnancy may activate certain protective mechanisms in babies. Psychologists from the University of Basel together with international colleagues report that certain epigenetic adaptations in newborns suggest this conclusion. Their results have been published in the journal Social Cognitive and Affective Neuroscience.
In their study, the researchers observed that increased concentrations of maternal stress hormones, depressive symptoms and general adversities during pregnancy were accompanied by epigenetic changes in the child. As a result of these changes the oxytocin receptor gene, which is important for social behavior and stress adaptations, is activated more easily. This mechanism could indicate that in these cases, the babies adapt to develop more resilience to cope with future challenges and adversities.
Switch reprogrammed
Whether a gene can be activated or not also depends on methyl groups that attach to the DNA and function as a switch. The researchers found that children from mothers with increased stress and depressive symptoms show a reduced methylation of the oxytocin receptor gene at birth. This results in the gene becoming more easily activated, which leads to a facilitated production of oxytocin receptors for oxytocin to react with and unfold its effects. Oxytocin not only has an important function in mother-child bonding and in induction of labor and lactation, it also influences social behavior.
For their study, the team of Prof. Gunther Meinlschmidt from the Faculty of Psychology at the University of Basel examined 100 mothers and their babies during and after pregnancy. They collected umbilical cord blood from 39 newborns and assessed the stress hormone cortisol in saliva samples of the mothers. In addition, the researchers evaluated stressful life events and mental health of the mothers via questionnaires. Since the data were only analyzed up to the newborn phase, no conclusions were drawn with regard to the long-term consequences that the epigenetic programming of oxytocin receptors might have for the children.
"Resilience research only at the beginning"
Researchers from the University of Basel, Ruhr University Bochum, Exeter University, McGill University Montreal, Ludwig Maximilian University of Munich, University of Trier, Zurich University of Applied Sciences and the Stress Center Trier were involved in this study funded by the Swiss National Science Foundation. Previous studies have shown, that adversities during pregnancy can increase the risk for mental disorders and physical diseases in the mother's offspring. However, science has so far dedicated much less attention to potential protective mechanisms of the child.
"Resilience research in this area is only at the beginning," explains Meinlschmidt. The observations made provide first evidence that an adverse environment during pregnancy could also activate protective mechanisms. "We need a comprehensive understanding of the psychological processes that allow humans to sustain long-term health even over generations despite adversities," says Meinlschmidt. Based on this knowledge, resilience processes could be promoted in order to try preventing the development of mental disorders and physical illnesses.
https://www.sciencedaily.com/releases/2016/05/160513084542.htm
Depressed moms not ‘in sync’ with their children
May 5, 2016
Science Daily/Binghamton University, State University of New York
Mothers with a history of depression are not physiologically "in sync" with their kids, according to a new study. While researchers have known for a while that depression is associated with interpersonal problems with others, this is the first study to examine whether this is also evident physiologically.
"When people are interacting, sometimes you just feel like you're in sync with somebody, and you know the interaction is going really well and you're enjoying the conversation. We're trying to figure out, at the body level, in terms of your physiology, do you see this synchrony in moms and their kids, and then how is that impacted by depression?" said Brandon Gibb, professor of psychology at Binghamton University and director of the Mood Disorders Institute and Center for Affective Science.
Binghamton researchers measured heart rate variability, a physiological measure of social engagement, in children aged 7-11 and their mothers (44 with a history of depression, 50 with no history of depression) while they engaged in positive and negative discussions. In the first discussion, mother-child pairs planned a dream vacation together; in the second discussion, pairs addressed a recent topic of conflict between them (e.g. homework, using the TV or computer, being on time, problems at school, lying, etc.) While moms with no history of depression displayed physiological synchrony (similar increases or decreases in heart rate variability) as their children during negative discussion, depressed moms were not in sync with their children. Furthermore, children and mothers who were more sad during the interaction were more likely to be out of sync with one another. According to researchers, these results provide preliminary evidence that synchrony during interactions is disrupted at the physiological level in families with a history of maternal depression and may be a potential risk factor for the intergenerational transmission of depression.
"We found that mothers who had no history of depression were really matching their children's physiology in the moment," said graduate student and lead author of the study Mary Woody. "We saw most moment-to-moment matching in the conflict discussion, in which they were talking about something negative going on in their life. In this difficult discussion, we're seeing this protective physiological mechanism coming out. Whereas, with mothers with a history of depression and their kids, we're seeing the opposite -- they actually mismatched. As one person is getting more engaged, the other person is pulling away. So they were really missing each other in that moment and walking away from the discussion feeling sad."
https://www.sciencedaily.com/releases/2016/05/160505105019.htm
Women do ask for pay rises but don’t get them
September 5, 2016
Science Daily/University of Warwick
New research shows that women ask for wage rises just as often as men, but men are 25 per cent more likely to get a raise when they ask.
Using a randomly chosen sample of 4,600 workers across more than 800 employers, the research is the first to do a statistical test of the idea that women get paid less because they are not as pushy as men. The researchers found no support for the theory.
The authors of the study "Do Women Ask?" also examined the claim that female employees hold back for fear of upsetting their boss, and again found no evidence for this theory either.
Co-author Andrew Oswald, Professor of Economics and Behavioural Science at the University of Warwick said: "We didn't know how the numbers would come out. Having seen these findings, I think we have to accept that there is some element of pure discrimination against women."
Various ideas have previously been suggested as to why women might be reluctant to ask for an increase in their pay packet. These include: women don't want to deviate from a perceived female stereotype, and they may fear being less popular at work.
Co-author Dr Amanda Goodall at Cass Business School said: "Ours is the first proper test of the reticent-female theory, and the evidence doesn't stand up."
When like-for-like men and women were compared, the men were a quarter more likely to be successful, obtaining a pay increase 20 per cent of the time. Only 16 per cent of females were successful when they asked.
The research uses data gathered in the Australian Workplace Relations Survey (AWRS) which covers the period 2013-14 which is a representative sample of Australian employees and workplaces. Professor Oswald said: "We realised that Australia was the natural test bed, because it is the only country in the world to collect systematic information on whether employees have asked for a rise."
The survey has the distinctive feature that it asks individuals a set of questions about whether their pay is set by negotiation with the company, whether they have successfully obtained a wage rise since joining the employer, whether they preferred not to attempt to negotiate a pay rise because they were concerned about their relationships, why they decided that, and about their levels of job satisfaction.
Using statistical methods, the authors' analysis shows that it is crucial to adjust for the number of hours worked (because part-time workers feel hesitant to 'ask'). The analysis also took into account the nature of the employer, the industry, and the characteristics and qualifications of workers.
Despite the dispiriting findings, the authors pinpointed one encouraging sign in the data -- young Australian female employees get pay hikes just as often as young Australian men.
Dr Goodall said: "This study potentially has an upside. Young women today are negotiating their pay and conditions more successfully than older females, and perhaps that will continue as they become more senior."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/09/160905130017.htm
How beardedness affects women's attraction to men
September 12, 2016
Science Daily/Wiley
New research suggests that women tend to find beardedness attractive when judging long-term relationships, perhaps as a signal of formidability among males and the potential to provide direct benefits, such as enhanced fertility and survival, to females.
For the study, investigators used computer graphic manipulation to morph male faces varying in facial hair from clean-shaven, light stubble, heavy stubble, and full beards, with additional differences in brow ridge, cheekbones, jawline, and other features so that the same man appeared more or less masculine.
When women viewed the images, masculinized and, to an even greater extent, feminized faces were less attractive than unmanipulated faces when all were clean-shaven. Stubble was judged as most attractive overall and received higher ratings for short-term relationships than full beards, which were more attractive for long-term relationships. Extremely masculine and extremely feminine-looking males were least attractive, irrespective of relationship context.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/09/160912141545.htm
Could quality of sleep have to do with sex differences?
September 12, 2016
Science Daily/McGill University
You may have noticed that women are more prone to sleep disturbances than men. They are, for instance, up to twice as likely to suffer from insomnia than men. Could there be a link between the body clock that regulates sleep and being a female or a male? Yes, according to a new study.
By controlling for the menstrual cycle and hormonal contraceptive use, Dr. Boivin shows, in the Proceedings of the National Academy of Sciences (PNAS), that the body clock affects sleep and alertness differently in men and women.
"For a similar sleep schedule, we find that women's body clock causes them to fall asleep and wake up earlier than men. The reason is simple: their body clock is shifted to a more easterly time zone," says the Director of the Centre for Study and Treatment of Circadian Rhythms at the Douglas Institute, one of the research centres of the CIUSSS de l'Ouest-de-l'Île-de-Montréal.
And, she adds, "This observed difference between the sexes is essential for understanding why women are more prone to disturbed sleep than men."
A novel experiment
In this study, the medical researcher's team compared in 15 men and 11 women variations in sleep and alertness regulated by the body clock. The women who were recruited were cycling naturally and were studied during two phases of their menstrual cycle. This is a crucial point because previous research by Dr. Boivin had shown that the phase of the menstrual cycle affects the biological rhythms of body temperature and sleep.
"Our participants did not exhibit any sleep problems during the study. Just the same, our results are helping us understand, among other things, why women are more likely than men to wake up earlier in the morning and feel tired after a night's sleep. As well, women are less alert at night than men," explains Boivin.
Thus, the results of this study hint that women could be less biologically suited for night work. Further research will be necessary to explore this matter and develop interventions suited to men's and women's health.
More than a third of the Canadian population experiences sleep disturbances. One consequence of this is that close to 15% of adults have functional problems.
https://www.sciencedaily.com/releases/2016/09/160912161058.htm
Depression in early pregnancy linked to gestational diabetes
September 19, 2016
Science Daily/National Institutes of Health
A two-way link between depression and gestational diabetes has been uncovered by researchers. Women who reported feeling depressed during the first two trimesters of pregnancy were nearly twice as likely to develop gestational diabetes, according to an analysis of pregnancy records. Conversely, a separate analysis found that women who developed gestational diabetes were more likely to report postpartum depression six weeks after giving birth, compared to a similar group of women who did not develop gestational diabetes.
https://images.sciencedaily.com/2016/09/160919094450_1_540x360.jpg
Pregnant woman having her blood sugar/ glucose checked.
Credit: © Mediteraneo / Fotolia
Gestational diabetes is a form of diabetes (high blood sugar level) occurring only in pregnancy, which if untreated may cause serious health problems for mother and infant.
"Our data suggest that depression and gestational diabetes may occur together," said the study's first author, Stefanie Hinkle, Ph.D., staff scientist in the Division of Intramural Population Health Research at the NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). "Until we learn more, physicians may want to consider observing pregnant women with depressive symptoms for signs of gestational diabetes. They also may want to monitor women who have had gestational diabetes for signs of postpartum depression."
Although obesity is known to increase the risk for gestational diabetes, the likelihood of gestational diabetes was higher for non-obese women reporting depression than for obese women with depression.
The researchers analyzed pregnancy records from the NICHD Fetal Growth Studies-Singleton Cohort, which tracked the progress of thousands of pregnancies, to understand the patterns of fetal growth. The study enrolled 2,334 non-obese and 468 obese women in weeks eight to 13 of pregnancy. The women responded to questionnaires on symptoms of depression when they enrolled in the study, again between the 16th and 22nd week of pregnancy, and then six weeks after giving birth. The researchers also reviewed the women's records to identify who had developed gestational diabetes.
"Of particular note, persistent depression from the first to second trimester set women at even greater risk for gestational diabetes" said the study's senior author, Cuilin Zhang, M.D., Ph.D, in the Division of Intramural Population Health Research at NICHD. Women who had the highest scores for depression in the first and second trimesters -- about 17 percent -- had nearly triple the risk for gestational diabetes when compared to women who had lower depression scores.
"Our results suggest it would be a good idea for clinicians to pay particular attention to women with high depression scores when evaluating the risk of gestational diabetes," Dr. Zhang added.
Although obesity increases the risk for gestational diabetes, non-obese women with high depression scores had nearly triple the risk for gestational diabetes than the other women in the study. Depression did not appear to increase the risk for gestational diabetes among obese women.
Currently, the American College of Obstetricians and Gynecologists recommends (link is external) that physicians screen patients at least once for depression during the perinatal period (link is external) (22 weeks of pregnancy through 7 days after birth.)
The researchers also found a higher risk for postpartum depression among the women who had gestational diabetes. Of the women who developed gestational diabetes, nearly 15 percent experienced depressive symptoms after birth, which was more than four times that of women who had not had gestational diabetes.
Dr. Hinkle stressed that the study was not able to prove a cause and effect relationship between symptoms of depression and gestational diabetes. The researchers added that earlier studies have shown that depression is associated with impaired glucose metabolism that may lead to higher blood sugar levels. Similarly, high blood sugar levels may lead to inflammation, hormonal, and other changes that could lead to symptoms of depression.Gestational diabetes is a form of diabetes (high blood sugar level) occurring only in pregnancy, which if untreated may cause serious health problems for mother and infant.
"Our data suggest that depression and gestational diabetes may occur together," said the study's first author, Stefanie Hinkle, Ph.D., staff scientist in the Division of Intramural Population Health Research at the NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). "Until we learn more, physicians may want to consider observing pregnant women with depressive symptoms for signs of gestational diabetes. They also may want to monitor women who have had gestational diabetes for signs of postpartum depression."
Although obesity is known to increase the risk for gestational diabetes, the likelihood of gestational diabetes was higher for non-obese women reporting depression than for obese women with depression.
The researchers analyzed pregnancy records from the NICHD Fetal Growth Studies-Singleton Cohort, which tracked the progress of thousands of pregnancies, to understand the patterns of fetal growth. The study enrolled 2,334 non-obese and 468 obese women in weeks eight to 13 of pregnancy. The women responded to questionnaires on symptoms of depression when they enrolled in the study, again between the 16th and 22nd week of pregnancy, and then six weeks after giving birth. The researchers also reviewed the women's records to identify who had developed gestational diabetes.
"Of particular note, persistent depression from the first to second trimester set women at even greater risk for gestational diabetes" said the study's senior author, Cuilin Zhang, M.D., Ph.D, in the Division of Intramural Population Health Research at NICHD. Women who had the highest scores for depression in the first and second trimesters -- about 17 percent -- had nearly triple the risk for gestational diabetes when compared to women who had lower depression scores.
"Our results suggest it would be a good idea for clinicians to pay particular attention to women with high depression scores when evaluating the risk of gestational diabetes," Dr. Zhang added.
Although obesity increases the risk for gestational diabetes, non-obese women with high depression scores had nearly triple the risk for gestational diabetes than the other women in the study. Depression did not appear to increase the risk for gestational diabetes among obese women.
Currently, the American College of Obstetricians and Gynecologists recommends (link is external) that physicians screen patients at least once for depression during the perinatal period (link is external) (22 weeks of pregnancy through 7 days after birth.)
The researchers also found a higher risk for postpartum depression among the women who had gestational diabetes. Of the women who developed gestational diabetes, nearly 15 percent experienced depressive symptoms after birth, which was more than four times that of women who had not had gestational diabetes.
Dr. Hinkle stressed that the study was not able to prove a cause and effect relationship between symptoms of depression and gestational diabetes. The researchers added that earlier studies have shown that depression is associated with impaired glucose metabolism that may lead to higher blood sugar levels. Similarly, high blood sugar levels may lead to inflammation, hormonal, and other changes that could lead to symptoms of depression.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/09/160919094450.htm
For women, caffeine could be ally in warding off dementia
October 3, 2016
Science Daily/Oxford University Press USA
Among a group of older women, self-reported caffeine consumption of more than 261 mg per day was associated with a 36 percent reduction in the risk of incident dementia over 10 years of follow-up. This level is equivalent to two to three 8-oz cups of coffee per day, five to six 8-oz cups of black tea, or seven to eight 12-ounce cans of cola.
"The mounting evidence of caffeine consumption as a potentially protective factor against cognitive impairment is exciting given that caffeine is also an easily modifiable dietary factor with very few contraindications," said Ira Driscoll, PhD, the study's lead author and a professor of psychology at the University of Wisconsin-Milwaukee. "What is unique about this study is that we had an unprecedented opportunity to examine the relationships between caffeine intake and dementia incidence in a large and well-defined, prospectively-studied cohort of women."
The findings come from participants in the Women's Health Initiative Memory Study, which is funded by the National Heart, Lung, and Blood Institute. Driscoll and her research colleagues used data from 6,467 community-dwelling, postmenopausal women aged 65 and older who reported some level of caffeine consumption. Intake was estimated from questions about coffee, tea, and cola beverage intake, including frequency and serving size.
In 10 years or less of follow-up with annual assessments of cognitive function, 388 of these women received a diagnosis of probable dementia or some form of global cognitive impairment. Those who consumed above the median amount of caffeine for this group (with an average intake of 261 mg per day) were diagnosed at a lower rate than those who fell below the median (with an average intake of 64 mg per day). The researchers adjusted for risk factors such as hormone therapy, age, race, education, body mass index, sleep quality, depression, hypertension, prior cardiovascular disease, diabetes, smoking, and alcohol consumption.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/10/161003143558.htm
All work and no play with children make moms less happy parents
October 4, 2016
Science Daily/University of Minnesota
Researchers have used time diary data to find that mothers are less happy than fathers with their parenting duties. Mothers report more stress and greater fatigue than fathers. This experience gap is attributed to the differing tasks of each parent.
"The good news from our study is that parents generally enjoy being with their kids," said University of Minnesota researcher Ann Meier, "but the bad news is that mothers enjoy it less than fathers because they do more of the 'work' and less of the 'fun' parenting tasks."
Meier and her colleagues Kelly Musick at Cornell University and Sarah Flood at the Minnesota Population Center used time diary data from more than 12,000 parents that linked to their feelings in the 2010, 2012, and 2013 American Time Use Survey. The team examined the types of parenting activities mothers and fathers performed and individual well-being during the activities.
The researchers found that not only do parenting activities between mothers and fathers differ, the environment surrounding the activity differs as well. Meier explained, "when mothers are with their kids, they are more often by themselves. When fathers are with their kids, they are more likely to have other adults around, offering some back-up. This helps us understand why fathers are less stressed when with kids."
Sleep also had an effect on parents' differing levels of happiness, said Meier. "Mothers are more likely than fathers to be called on by kids 'around the clock.' Fathers' sleep and down-time are less likely than mothers' to be interrupted by kids. This is part of the reason fathers are less tired than mothers when parenting."
The new paper confirms what many mothers have noted anecdotally. The data around parenting, activities, and happiness may help close the experience gap between genders. Meier says, "Having data systematically collected from thousands of parents allows us to confirm what parents have known for years -- that parenting is meaningful but also stressful and tiring. Many mothers will recognize their experiences of interrupted sleep and daily feeding and bathing. Hopefully, many dads will see that their partners will likely be happier if they trade some of their leisure time with kids for more of the 'work' of parenting."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/10/161004140217.htm
ADHD diagnosis puts girls at much higher risk for other mental health problems
October 4, 2016
Science Daily/University of California - Los Angeles
Girls with attention deficit hyperactivity disorder are at higher risk than girls without ADHD for multiple mental disorders that often lead to cascading problems such as abusive relationships, teenage pregnancies, poor grades and drug abuse, psychologists report.
The researchers, who conducted by far the most comprehensive analysis of girls and ADHD, report:
• 37.7 percent of girls with ADHD met criteria for an anxiety disorder, compared with only 13.9 percent of girls without ADHD.
• 10.3 percent of girls with ADHD were diagnosed with depression compared with only 2.9 percent without ADHD.
• 42 percent of girls with ADHD were diagnosed with oppositional defiant disorder, compared with just 5 percent of girls without it. Oppositional defiant disorder is characterized by angry, hostile, irritable, defiant behavior. To meet the diagnosis for oppositional defiant disorder, a child must display at least four of eight symptoms for at least six months that result in significant academic, social and family problems.
• 12.8 percent of girls with ADHD were diagnosed with conduct disorder compared with only 0.8 percent without ADHD. Conduct disorder is similar to oppositional defiant disorder, but with more severe behavioral problems, such as committing violent acts, setting fires and hurting animals.
"We knew the girls with ADHD would have more problems than the girls without ADHD, but we were surprised that conduct disorder and oppositional defiant disorder were at the top of the list, not depression or anxiety," said Steve Lee, a UCLA associate professor of psychology and senior author of the study. "These conduct disorders, more than anxiety and depression, predict severe adult impairments, such as risky sexual behavior, abusive relationships, drug abuse and crime."
Symptoms of ADHD include being easily distracted, fidgeting, being unable to complete a single task and being easily bored. The disorder occurs in approximately 5 percent to 10 percent of children in the United States, and figures in many other industrialized countries with compulsory education are comparable, Lee said. ADHD can begin in pre-school kids and can persist into high school and into adulthood, especially when it's accompanied by oppositional conduct disorder.
The psychologists analyzed 18 studies of 1,997 girls, about 40 percent (796) of whom had ADHD. Most of the girls were between ages 8 and 13. Most ADHD studies focused on boys, or compared girls with ADHD to boys with ADHD -- not to girls without ADHD.
ADHD is often harder to detect in girls than in boys because girls with the disorder may appear disengaged, forgetful or disorganized, and perceived as "spacey" and stay "under the radar" without being referred for assessment and treatment, said lead author Irene Tung, a UCLA graduate student in psychology and National Science Foundation graduate research fellow.
Fewer indications of ADHD in children whose mothers took vitamin D during pregnancy
October 7, 2016
Science Daily/University of Southern Denmark Faculty of Health Sciences
Children of mothers who took vitamin D during pregnancy with resultant high levels of the vitamin in the umbilical blood have fewer symptoms of ADHD at the age of 2½ years.
These were the findings in a new study from the Odense Child Cohort just published in The Australia & New Zealand Journal of Psychiatry.
"And for every 10 nmol/L increase in the vitamin D concentration in umbilical blood, the risk of a being among the 10% highest score on the ADHD symptom scale fell by 11%," explains one of the study's initiators, Professor Niels Bilenberg.
1,233 children from Odense Municipality were monitored in the study. Vitamin D was measured in umbilical blood, and mothers completed the Child Behavior Checklist (CBCL) when their child was 2½ years old. The CBCL questionnaire can be used to identify early symptoms of ADHD, even though an ADHD diagnosis cannot be made at that age.
"And the trend was clear: those mothers who had taken vitamin D, and had a vitamin D level (25OHD) in their umbilical blood over 25 nmol/L, had children with lower ADHD scores," continues Bilenberg. "This was after we had corrected for other factors that could explain the link, such as the mother's age, smoking, alcohol, obesity, education, number of children, psychiatric disease in the parents, child's sex, age and seasonal variation."
The link between vitamin D and early ADHD symptoms has not been described before, and has therefore attracted attention.
"We were very surprised that the link was so clear," say two of the study's other authors, medical students Jens Bull Aaby and Mats Mossin, "as there was no previous awareness that this link could be identified at such an early age. It's impossible to say with which children will develop ADHD later on, but it will be interesting to further follow up those children who were at the highest end versus the normal range of the ADHD scale."
The study offers no explanation as to how vitamin D can protect against ADHD, but other studies have shown that vitamin D plays an important role in the early development of the brain.
"We had an idea about it," says Aaby, "but we cannot say with certainty that vitamin D protects against early symptoms of ADHD. Our study only indicates that there is a link that we cannot explain in any other way."
Facts: Odense Børnekohorte is a joint study between Odense University Hospital, the Psychiatric Service of the Region of Southern Denmark, Odense Municipality, and the University of Southern Denmark. In the study, 2,500 mothers and their children are being monitored from early pregnancy to the child's 18th birthday. The children are now 3-5 years old and a number of follow-up studies are planned.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/10/161007105202.htm
Your fingers show your athletic potential and anxiety
October 12, 2016
Science Daily/The Norwegian University of Science and Technology (NTNU)
By comparing your index and ring fingers, a neuroscientist can tell if you are likely to be anxious, or if you are likely to be a good athlete.
Both women and men with this characteristic are -- on average -- better equipped to solve mentally demanding 3D rotation tasks as adults. As a group, they also have better physical and athletic abilities, but are more prone to having ADHD and Tourette's syndrome.
Why on earth is this the case? Both boys and girls are exposed to testosterone in the womb. Everyone has different levels of male and female sex hormones. Some men have a lot of testosterone, some have less, and the same applies to women. Women who have received a lot of prenatal testosterone don't need much testosterone as adults.
The level of testosterone in utero affects one's finger length as an adult.
24 women and a drop of testosterone
"The relationship between the index finger and ring finger in particular indicates how much testosterone you have been exposed to in utero," says Carl Pintzka, a medical doctor and researcher at the National Competence Service for Functional MRI.
In his doctoral dissertation at NTNU, Pintzka investigated how the brain functions differently in women and men. As part of this study, he tested an established theory about the significance of finger length and how the brain works.
He measured the finger length of 42 women and gave half of them a drop of testosterone. The other half were given a placebo. Afterwards, the women had to solve various mental tasks.
Short index finger, more testosterone
"We could then look at how testosterone levels affect different abilities in healthy women both in the womb and in adulthood," says Pintzka.
An index finger that is relatively short compared to the ring finger indicates that one has been exposed to a lot of testosterone in utero, whereas a relatively long index finger suggests a lower exposure to testosterone in the womb.
"One mechanism behind this relationship is the difference in the receptor density for oestrogen and testosterone in the various fingers in utero. This relationship has also been shown to remain relatively stable after birth, which implies that it's strictly the fetal hormone balance that determines this ratio," says Pintzka.
More testosterone, better sense of place
The relationship between the index finger and ring finger in humans is associated with a variety of abilities in adulthood.
"The greatest effect has been found for various physical and athletic measures, where high levels of prenatal testosterone are consistently linked with better capabilities," Pintzka says. "Beyond this we find a number of uncertain results, but a general feature is that high levels of testosterone generally correlate with superior abilities on tasks that men usually perform better, such as various spatial tasks like directional sense," he adds.
Conversely, low levels of testosterone are associated with better abilities in verbal memory tasks, such as remembering lists of words. Fetal hormonal balance also likely affects the risk of developing various brain-related diseases.
… but also more ADHD and autism
Pintzka says studies show that high levels of testosterone in utero correlate with an increased risk of developing diseases that are more common in men, such as ADHD, Tourette's and autism. Low levels of testosterone are associated with an increased risk of developing diseases that are more common in women, like anxiety and depression.
His study primarily involved researching how testosterone affects different spatial abilities in women. The women were asked to navigate a virtual maze, and to mentally rotate different three-dimensional objects.
More study needed According to Pintzka, the study results indicate a trend towards a positive effect of high testosterone levels on spatial abilities in utero. He believes that a larger study would be able to show a significant correlation. Furthermore, the results suggest that these hormone levels are important both in utero and in adulthood.
In other words, no definite conclusions can be drawn quite yet. Pintzka found no prenatal hormonal effects on study participants' ability to navigate a virtual maze.
"The women who scored best on the mental rotation tasks had high levels of testosterone both prenatally and in their adult lives, while those who scored worst had low levels in both," says Pintzka.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/10/161012095619.htm