1. Higher estrogen levels linked to increased alcohol sensitivity in brain’s ‘reward center’

    November 14, 2017 by Ashley

    From the University of Illinois at Chicago press release:

    The reward center of the brain is much more attuned to the pleasurable effects of alcohol when estrogen levels are elevated, an effect that may underlie the development of addiction in women, according to a study on mice at the University of Illinois at Chicago.

    Led by Amy Lasek, assistant professor of psychiatry in the UIC College of Medicine, researchers found that neurons in a region of the brain called the ventral tegmental area, or VTA (also known as the “reward center”), fired most rapidly in response to alcohol when their estrogen levels were high. This response, according to their findings published online in the journal PLOS ONE, is mediated through receptors on dopamine-emitting neurons in the VTA.

    “When estrogen levels are higher, alcohol is much more rewarding,” said Lasek, who is the corresponding author on the paper and a researcher in the UIC Center for Alcohol Research in Epigenetics. “Women may be more vulnerable to the effects of alcohol or more likely to overindulge during certain stages of their cycle when estrogen levels are higher, or may be more likely to seek out alcohol during those stages.”

    Studies indicate that gender differences in psychiatric disorders, including addiction, are influenced by estrogen, one of the primary female sex hormones. Women are more likely to exhibit greater escalation of abuse of alcohol and other drugs, and are more prone to relapse in response to stress and anxiety.

    The VTA helps evaluate whether something is valuable or good. When neurons in this area of the brain are stimulated, they release dopamine — a powerful neurotransmitter responsible for feelings of wellness — and, in large doses, euphoria. When something good is encountered — for example, chocolate — the neurons in the VTA fire more rapidly, enforcing reward circuitry that encodes the idea that chocolate is enjoyable and something to be sought out. Over time, the VTA neurons fire more quickly at the sight, or even thought of, chocolate, explained Lasek. In addiction, VTA neurons are tuned into drugs of abuse, and fire more quickly in relation to consuming or even thinking about drugs, driving the person to seek them out — often at the expense of their own health, family, friends and jobs.

    Many animal studies have shown that alcohol increases the firing of dopamine-sensitive neurons in the VTA, but little is known about exactly why this occurs.

    Lasek and her colleagues examined the relationship between estrogen, alcohol and the VTA in female mice. They used naturally cycling mice that were allowed to go through their normal estrous cycles, akin to the menstrual cycle in women.

    Mice were evaluated to determine when they entered diestrus — the phase in the estrous cycle when estrogen levels are close to their peak.

    “In mice in diestrus, estrogen levels increase to about 10 times higher than they are in estrus, the phase in which ovulation occurs and estrogen levels drop,” Lasek said.

    VTAs were taken from mice in both estrus and diestrus and kept alive in special chambers. Electrodes recorded the activity of individual dopamine-sensitive neurons in the VTA. Next, the researchers added alcohol to the chamber. Activity increased twice as much in neurons from mice in diestrus compared to the response of neurons from mice in estrus.

    Lasek and her colleagues then blocked estrogen receptors on dopamine-sensitive neurons in VTA in mice in estrus and diestrus. With the blocker present, the response to alcohol in neurons from mice in diestrus was significantly lower compared with neurons where estrogen receptors remained functional. The estrogen receptor blocker reduced the alcohol response to levels seen in mice in estrus. The responses to alcohol in neurons from mice in estrus were unaffected by the estrogen receptor blocker.

    “The increased reward response to alcohol we see when estrogen levels are high is mediated through receptors for estrogen in the VTA,” said Mark Brodie, professor of physiology and biophysics in the UIC College of Medicine and a co-author on the paper.

    Lasek believes that the increased sensitivity to alcohol in the VTA when estrogen levels peak may play a significant role in the development of addiction in women.

    “We already know that binge drinking can lead to lasting changes in the brain, and in women, those changes may be faster and more significant due to the interaction we see between alcohol, the VTA and estrogen,” Lasek said. “Binge drinking can increase the risk of developing alcoholism, so women need to be careful about how much alcohol they drink. They should be aware that they may sometimes inadvertently over-consume alcohol because the area of the brain involved in alcohol reward is responding very strongly.”


  2. Study suggests there may be potential cognitive benefits to hormone replacement therapy

    November 4, 2017 by Ashley

    From the University of Southern California press release:

    A type of hormone replacement therapy may protect memory for some women, according to a new USC-led study.

    The findings by USC researchers are the latest to indicate that hormone replacement therapy may have some benefits, deepening scientific discussions about the pros and cons of the menopausal treatment.

    “Our study suggests that estrogen treatment after menopause protects the memory that is needed for short-term cognitive tasks from the effects of stress,” said Alexandra Ycaza Herrera, the study’s lead author and a researcher at the USC Leonard Davis School of Gerontology.

    Earlier studies have pointed to potential health risks of the treatment. A combination therapy that uses both estrogen and progesterone has been linked to a higher risk of breast cancer, heart disease, stroke and blood clots.

    The study was published on Nov. 2 in the Journal of Clinical Endocrinology and Metabolism.

    The researchers found that women taking estrogen-only therapy had lower levels of the stress hormone cortisol and performed better on tests of “working memory” following exposure to stress compared to women taking a placebo.

    Working memory allows the brain to keep information immediately available for processing, such as when a shopper uses a mental grocery list to pick up items or when a student keeps specific numbers in mind as a teacher reads a word problem aloud in math class. Studies have documented that stress can impair working memory.

    To measure the effect of estrogen therapy on working memory under stress, Ycaza Herrera recruited 42 women with an average age of 66 from the USC Early versus Late Intervention Trial with Estradiol led by Howard Hodis, a professor at the Keck School of Medicine of USC and a coauthor of the new study.

    Half of the postmenopausal women had been on estradiol, a type of estrogen therapy, for approximately five years, while the others had received a placebo.

    Each participant visited USC twice. To induce a stress response during one visit, researchers asked participants to submerge their hand in ice water for about 3 minutes. For the control condition conducted during the other visit, the participants submerged their hand in warm water.

    Before and after each visit, the researchers collected saliva to measure the women’s levels of cortisol, estrogen, and progesterone. The researchers also ran a test of working memory called a “sentence span task,” in which the women were each given a series and then asked whether each sentence made sense. They also were asked to recall the last word of each one.

    All women performed equally well on the sentence span task after the warm water condition. But after the ice bath, women taking the placebo experienced a spike in cortisol levels. They also demonstrated a decrease in working memory function.

    By contrast, women receiving estrogen therapy had a smaller increase in cortisol and showed no decrease in working memory function.

    “Hormone replacement therapy may not be right for every woman, but women need to be able to have the conversation with their doctors,” Ycaza Herrera said.


  3. Study links testosterone to stock market instability

    October 14, 2017 by Ashley

    From the Institute for Operations Research and the Management Sciences press release:

    In the U.S. today, the majority of professional stock market traders are young males and new evidence suggests biology strongly influences their trading behavior. According to a new study in the INFORMS journal Management Science, this could be a significant contributor to fluctuations in the market, as high testosterone levels can cause these traders to overestimate future stock values and change their trading behavior, leading to dangerous prices bubbles and subsequent crashes.

    The study, “The Bull of Wall Street: Experimental Analysis of Testosterone and Asset Trading,” was conducted by Amos Nadler of the Ivey Business School at Western University, Peiran Jiao of the University of Oxford, Paul Zak and Veronika Alexander of the Center for Neuroeconomics Studies at Claremont Graduate University, and Cameron Johnson at the Behavioral Health Institute at Loma Linda.

    The double blind study involved 140 young males, each of whom received a topical gel containing either testosterone or a placebo, prior to participating in an experimental asset market in which they were able to post bid and ask prices, as well as buy and sell financial assets to earn real money.

    The authors found that among groups that received testosterone relative to those who received a placebo, larger price bubbles formed, mispricing lasted longer, market dynamics changed to reflect increasing bidding and selling volume, and their perception of a stock’s value changed despite its being displayed throughout the study. While the traders who received the placebo displayed “buy low to sell high” behavior, those who had received testosterone adhered to “buy high to sell higher.”

    “This research suggests the need to consider hormonal influences on decision-making in professional settings, because biological factors can exacerbate capital risk,” said Nadler. “Perhaps the simplest recommendation is to implement ‘cool down’ periods to interrupt exceptionally positive feedback cycles and return the focus to assets’ fundamental valuations to reduce the possibility of biased decision-making.”

    “Based on our findings, professional traders, investment advisories, and hedge funds should limit the risk taken by young male traders,” continued Nadler. “This is the first study to have shown that testosterone changes the way the brain calculates value and returns in the stock market and therefore — testosterone’s neurologic influence will cause traders to make suboptimal decisions unless systems prevent them from occurring.”


  4. Study examines effect of oxytocin on sociability

    October 8, 2017 by Ashley

    From the Stanford University Medical Center press release:

    Why is it so much fun to hang out with our friends? Why are some people so sociable while others are loners or seemingly outright allergic to interactions with others?

    A new study by researchers at the Stanford University School of Medicine begins to provide an answer, pinpointing places and processes in the brain that promote socialization by providing pleasurable sensations when it occurs. The findings point to potential ways of helping people, such as those with autism or schizophrenia, who can be painfully averse to socializing.

    The study, which will be published Sept. 29 in Science, details the role of a substance called oxytocin in fostering and maintaining sociability. The senior author is Robert Malenka, MD, PhD, professor and associate chair of psychiatry and behavioral science. The lead author is former postdoctoral scholar Lin Hung, PhD.

    “Our study reveals new insights about the brain circuitry behind social reward, the positive experience you often get when you run into an old friend or meet somebody you like,” said Malenka, who has focused much of his research on an assembly of interacting nerve tracts in the brain collectively known as the reward circuitry.

    “The reward circuitry is crucial to our survival because it rewards us for doing things that have, during our evolutionary history, tended to enhance our survival, our reproduction and the survival of our resulting offspring,” said Malenka, who holds the Nancy Friend Pritzker Professorship in Psychiatry and the Behavioral Sciences. “It tells us what’s good by making us feel good. When you’re hungry, food tastes great. When you’re thirsty, water is refreshing. Sex is great pretty much most of the time. Hanging out with your friends confers a survival advantage, too, by decreasing your chances of getting eaten by predators, increasing your chances of finding a mate and maybe helping you learn where food and water are.”

    Reward system conserved over evolution

    Because the reward system is so critical, it’s been carefully conserved over evolution and in many respects operates just the same way in mice as it does in humans, making mice good experimental models for studying it.

    Far and away the most important component of the brain’s reward circuitry, Malenka said, is a nerve tract that runs from a structure deep in the brain called the ventral tegmental area to a midbrain structure called the nucleus accumbens. The ventral tegmental area houses a cluster of nerve cells, or neurons, whose projections to the nucleus accumbens secrete a substance called dopamine, altering neuronal activity in this region. Dopamine release in the nucleus accumbens can produce a wave of pleasure, telling the brain that the event going on is helpful for survival. Dopamine release in this region, and subsequent changes in activity there and in downstream neurons, also prime the brain to remember the events and the behaviors leading up to the chemical’s release.

    This tract, so famous for reinforcing survival-enhancing behaviors such as eating, drinking and mating, has been infamously implicated in our vulnerability to drug addiction — a survival-threatening outcome resulting from drugs’ ability to inappropriately stimulate dopamine secretion in the tract. But understanding exactly how and under what natural conditions the firing of its dopamine-secreting nerves gets tripped off is a work in progress.

    Earlier research has specifically implicated dopamine release in the nucleus accumbens in social behavior. “So, we knew reward circuitry plays a role in social interactions,” Malenka said. “What we still didn’t know — but now we do — was: How does this increased dopamine release during social interaction come about?”

    ‘Love hormone’ pulls the strings

    It turns out that another chemical — oxytocin — is pulling the strings.

    Oxytocin is sometimes called the “love hormone” because it’s thought to be involved in falling in love, mother-child bonding and female sexual arousal, as well as lifetime pair-bonding of sexual mates among some species. The chief source of oxytocin in the brain is the paraventricular nucleus, which resides in a deep-brain structure called the hypothalamus that serves as a manifold master regulator of body temperature, hunger, thirst, sleep, emotional reactions and more.

    Research over the last 20 to 40 years has suggested that oxytocin plays a role in promoting not just sexual or nurturing behavior, but also sociability. A 2013 study co-authored by Malenka showed that oxytocin was essential to reinforcing friendly, social behavior in mice. But how that occurred was unclear, as the paraventricular nucleus sends oxytocin-squirting nerve tracts to many areas throughout the brain.

    So Malenka and his colleagues designed experiments to nail down oxytocin’s role in social behavior. They confirmed that a tract running from the paraventricular nucleus to the ventral tegmental area carried oxytocin. They showed, for the first time, that activity in this tract’s oxytocin-secreting neurons jumped during mice’s social interactions and that this neuronal activity was required for their normal social behavior. Disrupting this activity inhibited sociability but didn’t impair the mice’s movement or their appetite for pleasurable drugs, such as cocaine.

    The researchers demonstrated that oxytocin secreted in the ventral tegmental area by neurons originating in the paraventricular nucleus fosters sociability by binding to receptors on the dopamine-secreting neurons that compose the tract running from the ventral tegmental area to the nucleus accumbens, enhancing the firing of the reward-circuit tract.

    The findings should help translational researchers develop medications for individuals with neurological disorders, such as autism, depression and schizophrenia, whose conditions compromise their ability to experience pleasure from connecting with other people, Malenka said.

    But he also voiced a desire for more widespread applications of the research. “With so much hatred and anger in the world,” he said, “what could possibly be more important than understanding the mechanisms in the brain that make us want to be friendly with other people?”


  5. Study links dogs’ social skills to oxytocin sensitivity

    October 5, 2017 by Ashley

    From the Linköping University press release:

    The tendency of dogs to seek contact with their owners is associated with genetic variations in sensitivity for the hormone oxytocin, according to a new study from Linköping University, Sweden. The results have been published in the scientific journal Hormones and Behavior and contribute to our knowledge of how dogs have changed during their development from wolf to household pet.

    During their domestication from their wild ancestor the wolf to the pets we have today, dogs have developed a unique ability to work together with humans. One aspect of this is their willingness to “ask for help” when faced with a problem that seems to be too difficult. There are, however, large differences between breeds, and between dogs of the same breed. A research group in Linköping, led by Professor Per Jensen, has discovered a possible explanation of why dogs differ in their willingness to collaborate with humans.

    The researchers suspected that the hormone oxytocin was involved. It is well-known that oxytocin plays a role in social relationships between individuals, in both humans and animals. The effect of oxytocin depends on the function of the structure that it binds to, the receptor, in the cell. Previous studies have suggested, among other things, that differences in dogs’ ability to communicate are associated with variations in the genetic material located close to the gene that codes for the oxytocin receptor. The researchers in the present study examined 60 golden retrievers as they attempted to solve an insoluble problem.

    “The first step was to teach the dogs to open a lid, and in this way get hold of a treat. After this, they were given the same task with the lid firmly fixed in place, and thus impossible to open. We timed the dogs to see how long they attempted on their own, before turning to their owner and asking for help,” says Mia Persson, PhD student at the Department of Physics, Chemistry and Biology, and principal author of the article.

    Before the behavioural test, the researchers increased the levels of oxytocin in the dogs’ blood by spraying the hormone into their nose. As a control, the dogs carried out the same test after having received a spray of neutral salt water in the same way. The researchers also collected DNA using a cotton swab inside the dogs’ cheek, and determined which variant of the gene for the oxytocin receptor that each dog had.

    The results showed that dogs with a particular genetic variant of the receptor reacted more strongly to the oxytocin spray than other dogs. The tendency to approach their owner for help increased when they received oxytocin in their nose, compared with when they received the neutral salt water solution. The researchers suggest that these results help us understand how dogs have changed during the process of domestication. They analysed DNA also from 21 wolves, and found the same genetic variation among them. This suggests that the genetic variation was already present when domestication of the dogs started, 15,000 years ago.

    “The results lead us to surmise that people selected for domestication wolves with a particularly well-developed ability to collaborate, and then bred subsequent generations from these,” says Mia Persson.

    The genetic variations that the researchers have studied do not affect the oxytocin receptor itself: they are markers used for practical reasons. Further research is necessary to determine in more detail which differences in the genetic material lie behind the effects.

    Per Jensen points out that the study shows how social behaviour is to a large extent controlled by the same genetic factors in different species.

    “Oxytocin is extremely important in the social interactions between people. And we also have similar variations in genes in this hormone system. This is why studying dog behaviour can help us understand ourselves, and may in the long term contribute to knowledge about various disturbances in social functioning,” he says.


  6. Study suggests oxytocin can intensify both positive and negative experiences

    September 30, 2017 by Ashley

    From the University of California – Davis press release:

    Before you shop for the “cuddle” hormone oxytocin to relieve stress and enhance your social life, read this: a new study from the University of California, Davis, suggests that sometimes, blocking the action of oxytocin in the brain may be a better option. The results are published online in the journal Biological Psychiatry.

    Sometimes popularly called the “love hormone,” oxytocin is a hormone released in the brain that plays a major role in social relationships. The new work by behavioral neuroscientists Natalia Duque-Wilckens and Brian Trainor shows that after negative social interactions, oxytocin promotes avoidance of unfamiliar social situations.

    Trainor and Duque-Wilckens worked with female California mice. When stressed, these mice can show a form of social anxiety, staying away from unfamiliar mice instead of approaching. The new study shows that a single dose of a drug that blocks the activity of oxytocin restored normal social behavior in stressed females.

    The result is exciting because “for antidepressants like Prozac to have this same effect, it takes a month of daily treatment,” said Trainor, a professor in the UC Davis Department of Psychology, College of Letters and Science.

    This outcome was expected based on a previous study from the lab, which showed that social stress increased the activity of oxytocin-producing cells in the brain and that females given intranasal oxytocin avoided new social contexts.

    Amplifying Positive and Negative Effects

    Postdoctoral researcher Duque-Wilckens said that these findings support the theory that oxytocin amplifies the effects of social experiences. That is, rather than promoting positive social interactions, oxytocin intensifies the experience of both positive and negative social interactions.

    In a positive context, such as with family or friends, oxytocin could promote social approach behavior (hence the “cuddling” hormone). However, in a negative context, like bullying, oxytocin could promote social avoidance. One question left unanswered by this theory is how the same hormone could have such different effects on behavior. The new study led by Duque-Wilckens provides an explanation.

    The team found that two brain regions responded to oxytocin more strongly in females than males. These regions were the bed nucleus of the stria terminalis (BNST), a brain region known to control anxiety, and the nucleus accumbens, a brain region important for reward and motivation. Duque-Wilckens found that injecting an oxytocin blocker into the BNST, but not the nucleus accumbens, reversed the effects of stress on social behavior in females. Work by other researchers has shown that oxytocin acting in the nucleus accumbens promotes rewarding aspects of social interactions.

    Together, these findings suggest that oxytocin can generate social anxiety or reward by acting in different parts of the brain. At times when oxytocin is acting in the BNST, drugs that inhibit oxytocin could reduce social anxiety.

    Trainor said a consistent theme in oxytocin research is that experience and the surrounding environment have important effects on how oxytocin affects behavior.

    “Stressful social experiences appear to change which parts of the brain use oxytocin,” he said. “Understanding how this works in a mouse gives us new ideas on how we could use drugs targeting oxytocin to reduce social anxiety.”


  7. Study links dimensions of a person’s face with their sex drive

    September 28, 2017 by Ashley

    From the Springer press release:

    Men and women with shorter, wider faces tend to be more sexually motivated and to have a stronger sex drive than those with faces of other dimensions. These are the findings from a study led by Steven Arnocky of Nipissing University in Canada. The research investigates the role that facial features play in sexual relationships and mate selection and is published in Springer’s journal Archives of Sexual Behavior.

    The study adds to a growing body of research that has previously shown that certain psychological and behavioral traits are associated with particular facial width-to-height ratios (known as FWHR). Square-faced men (who therefore have a high FWHR) tend to be perceived as more aggressive, more dominant, more unethical, and more attractive as short-term sexual partners than their thinner and longer-faced counterparts.

    Researchers attributed differences in facial proportions to variations in testosterone levels during particular developmental periods, such as puberty. This hormone plays a role in forming adult sexual attitudes and desires.

    In this paper, Arnocky and his colleagues report two separate studies conducted among students. In the first, 145 undergraduates who were in romantic relationships at the time completed questionnaires about their interpersonal behavior and sex drive. The researchers also used photographs of the participants to determine their facial width-to-height ratio. The second study involved 314 students and was an extended version of the first study, which included questions about participants’ sexual orientation, the chances of them considering infidelity, and their sociosexual orientation. The latter is a measure of how comfortable participants are with the concept of casual sex that does not include love or commitment.

    According to Arnocky, their findings suggest that FWHR can be used to predict a measure of sexuality in both sexes. Men and women with a high FWHR (therefore, square and wide faces) reported a greater sex drive than others.

    “Together, these findings suggest that facial characteristics might convey important information about human sexual motivations” , says Arnocky.

    It was also found that men with a larger FWHR not only have a higher sex drive than others, but also are more easy-going when it comes to casual sex and would consider being unfaithful to their partners.


  8. Study looks at effect of testosterone fluctuations in fathers after baby arrives

    September 19, 2017 by Ashley

    From the University of Southern California press release:

    Postpartum depression is often associated with mothers, but a new study shows that fathers face a higher risk of experiencing it themselves if their testosterone levels drop nine months after their children are born.

    The same study revealed that a father’s low testosterone may also affect his partner — but in an unexpectedly positive way. Women whose partners had lower levels of testosterone postpartum reported fewer symptoms of depression themselves nine and 15 months after birth.

    High testosterone levels had the opposite effect. Fathers whose levels spiked faced a greater risk of experiencing stress due to parenting and a greater risk of acting hostile- such as showing emotional, verbal or physical aggression — toward their partners.

    The study was published in the journal Hormones and Behavior on Sept. 1. The findings support prior studies that show men have biological responses to fatherhood, said Darby Saxbe, the study’s lead author and an assistant professor of psychology at USC Dornsife College of Letters, Arts and Sciences.

    “We often think of motherhood as biologically driven because many mothers have biological connections to their babies through breastfeeding and pregnancy.” Saxbe said. “We don’t usually think of fatherhood in the same biological terms. We are still figuring out the biology of what makes dads tick.

    “We know that fathers contribute a lot to child-rearing and that on the whole, kids do better if they are raised in households with a father present,” she added. “So, it is important to figure out how to support fathers and what factors explain why some fathers are very involved in raising their children while some are absent.”

    Saxbe worked with a team of researchers from USC, University of California at Los Angeles and Northwestern University.

    A snapshot of paternal postpartum depression

    For the study, the researchers examined data from 149 couples in the Community Child Health Research Network. The study by the National Institute for Child Health and Human Development involves sites across the country, but the data for this study came from Lake County, Illinois, north of Chicago.

    Mothers in the study were 18 to 40 years old; African-American, white or Latina; and low-income. They were recruited when they gave birth to their first, second or third child. Mothers could invite the baby’s father to participate in the study as well. Of the fathers who participated and provided testosterone data, 95 percent were living with the mothers.

    Interviewers visited couples three times in the first two years after birth: around two months after the child was born, about nine months after birth and about 15 months after birth.

    At the nine-month visit, researchers gave the fathers saliva sample kits. Dads took samples three times a day — morning, midday and evening — to monitor their testosterone levels.

    Participants responded to questions about depressive symptoms based on a widely-used measure, the Edinburgh Postnatal Depression. They also reported on their relationship satisfaction, parenting stress and whether they were experiencing any intimate partner aggression. Higher scores on those measures signaled greater depression, more stress, more dissatisfaction and greater aggression.

    Relatively few participants — fathers and mothers — were identified as clinically depressed, which is typical of a community sample that reflects the general population. Instead of using clinical diagnoses, the researchers looked at the number of depressive symptoms endorsed by each participant.

    Men’s testosterone levels were linked with both their own and their partners’ depressive symptoms — but in opposing directions for men and for women.

    For example, lower testosterone was associated with more symptoms in dads, but fewer symptoms in moms. The link between their partners’ testosterone levels and their own depression was mediated by relationship satisfaction. If they were paired with lower-testosterone partners, women reported greater satisfaction with their relationship, which in turn helped reduce their depressive symptoms.

    “It may be that the fathers with lower testosterone were spending more time caring for the baby or that they had hormone profiles that were more synced up with mothers,” she said. “For mothers, we know that social support buffers the risk of postpartum depression.”

    Fathers with higher testosterone levels reported more parenting stress, and their partners reported more relationship aggression.

    To measure parenting stress, parents were asked how strongly they related to a set of 36 items from the Parenting Stress Index-Short Form. They responded to statements such as “I feel trapped by my responsibilities as a parent” and “My child makes more demands on me than most children.” A high number of “yes” responses signaled stress.

    Relationship satisfaction questions were based on another widely-used tool, the Dyadic Adjustment Scale. Parents responded to 32 items inquiring about their relationship satisfaction, including areas of disagreement or their degree of closeness and affection. Higher scores signaled greater dissatisfaction.

    Mothers also answered questions from another scientific questionnaire, the HITS (Hurts, Insults, and Threats Scale), reporting whether they had experienced any physical hurt, insult, threats and screaming over the past year. They also were asked if their partners restricted activities such as spending money, visiting family or friends or going places that they needed to go.

    “Those are risk factors that can contribute to depression over the long term,” Saxbe said.

    Treating fathers with postpartum depression

    Although doctors may try to address postpartum depression in fathers by providing testosterone supplements, Saxbe said that the study’s findings indicate a boost could worsen the family’s stress.

    “One take-away from this study is that supplementing is not a good idea for treating fathers with postpartum depression,” she said. “Low testosterone during the postpartum period may be a normal and natural adaptation to parenthood.”

    She said studies have shown that physical fitness and adequate sleep can improve both mood and help balance hormone levels.

    In addition, both mothers and fathers should be aware of the signs of postpartum depression and be willing to seek support and care, Saxbe said. Talk therapy can help dads — or moms — gain insight into their emotions and find better strategies for managing their moods.

    “We tend to think of postpartum depression as a mom thing,” Saxbe said. “It’s not. It’s a real condition that might be linked to hormones and biology.”


  9. Oxytocin and social norms reduce xenophobia

    August 29, 2017 by Ashley

    From the Universität Bonn press release:

    How can xenophobia be reduced and altruism strengthened? Researchers at University Hospital Bonn have shown in a new study that the bonding hormone oxytocin together with social norms significantly increases the willingness to donate money to refugees in need, even in people who tend to have a skeptical attitude towards migrants. The results are published in the Proceedings of the National Academy of Sciences (PNAS).

    We tend to be more altruistic to our own family and friends than to perfect strangers. The recent migration of Middle Eastern refugees into European societies has further magnified the issue, with a large divide in society between people who do and do not support the refugees. “This is partly due to evolution: Only through solidarity and cooperation within one’s own group was it possible to raise children and survive when competing against unknown and rivaling groups for scarce resources in pre-civilized times,” explains Prof. Rene Hurlemann from the Department of Psychiatry, University of Bonn Medical Center. However, this is diametrically opposed to the parable of the Good Samaritan, which serves as an example of selfless altruism by describing a Samaritan who incurs personal costs to help a stranger in need. “From a neurobiological perspective, the basis of xenophobia and altruism is not yet precisely understood,” says Hurlemann.

    Under the psychiatrist’s supervision, a team of researchers at the University of Bonn, the Laureate Institute for Brain Research in Tulsa (USA), and the University of Lübeck conducted three experiments in which they tested a total of 183 subjects, who were all German natives. In the Laboratory for Experimental Economics (BonnEconLab) at the University of Bonn, they completed a donation task on a computer. The donation task included 50 authentic case vignettes describing the personal needs of poor people, 25 of which were portrayed as local people in need, while the other 25 people were portrayed as refugees.

    With an endowment of 50 euros, the participants could decide for each individual case whether they wanted to donate a sum between zero and one euro. The test subjects were allowed to keep any money that was not donated. “We were surprised that the participants in the first experiment donated around 20 percent more to refugees than to local people in need,” says Nina Marsh from Prof. Hurlemann’s team.

    Questionnaire on attitude towards migrants

    In another independent experiment involving over 100 participants, the subjects’ personal attitudes towards refugees were assessed in a questionnaire. Then half of the group received the bonding hormone oxytocin via a nasal spray, while the other half of the group received a placebo before they were exposed to the donation task established in the first experiment: again the participants decided how much of their 50 euros they wanted to donate to locals or refugees.

    Under the influence of oxytocin, the individuals who tended to show a positive attitude towards refugees doubled their donations to both the locals and the refugees. However, oxytocin had no effect in individuals who expressed a rather defensive attitude towards migrants: In those participants, the tendency to donate was very low to locals and refugees alike. “Oxytocin clearly increases generosity towards those in need, however, if this altruistic fundamental attitude is missing, the hormone alone cannot create it,” says Hurlemann.

    Oxytocin in combination with social norms decreases xenophobia

    How can people who tend to have a xenophobic attitude be motivated to be more altruistic? The researchers assumed that the addition of social norms could be a starting point. In a third experiment, they thus presented the participants with the average donation their peers made in the first experiment under each case vignette. Half of the participants once again received oxytocin. The result was astounding. “Now, even people with negative attitudes towards migrants donated up to 74 percent more to refugees than in the previous round,” reports Nina Marsh. Through the combined administration of oxytocin with a social norm, the donations for refugees in those skeptical towards migrants nearly reached half of the sums donated by the group, which showed a positive attitude towards refugees.

    What conclusions can be drawn from these results? It appears that pairing oxytocin with a social norm can help counter the effects of xenophobia by enhancing altruistic behavior toward refugees. “The combined enhancement of oxytocin and peer influence could diminish selfish motives,” says Hurlemann. If people whom we trust, such as supervisors, neighbors or friends, act as a role model by making public their positive attitude towards refugees, more people would probably feel motivated to help. In such a prosocial context, oxytocin could increase trust and minimize anxiety — experience shows that the oxytocin level in the blood increases during social interaction and shared activities. “Given the right circumstances, oxytocin may help promote the acceptance and integration of migrants into Western cultures,” says Hurlemann.


  10. Study looks at links between competitiveness, aggression and hormone levels

    August 28, 2017 by Ashley

    From the University of Erlangen-Nuremberg press release:

    Feelings can run high in competitive situations and lead to heated arguments and disputes. But not everyone reacts in the same way — men react differently to women and the reactions of individuals are dissimilar to those of groups of persons. This has been demonstrated scientifically by psychologists at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) who examined the correlations between competitiveness, aggression and hormones. The researchers recently published their findings in the journal PLOS ONE.

    Participants in a laboratory study were required to master competitive tasks over ten rounds. They competed against each other either as individuals or as teams, whereby one side lost the competition and the other side won. Participants were allowed to give full rein to their aggressive impulses during the competition. For this purpose, at the beginning of each round, they were asked to specify how loud an unpleasant noise would be that the opponent would be required to listen to through headphones if they lost the round. Saliva samples were collected from the participants prior to and after the competition in order to document changes to hormone levels.

    Prof. Dr. Oliver Schultheiss and Dr. Jonathan Oxford from the Chair of General Psychology II at FAU found that men tended to behave more aggressively than women, that losers were more aggressive than winners and that teams were more aggressive than individuals. Furthermore, the researchers also detected a correlation between aggression and levels of the stress hormone cortisol; the more aggressively a person behaved, the lower their cortisol level was. “Our results show that the usual suspects are the ones who become aggressive — namely participants who are male and frustrated. But our analysis also revealed that it was easier for participants who were part of a team to attack others than it was for individuals. At the same time, elevation of stress hormones when encountering a threat that cannot be mastered is in actual fact associated with less aggression,” explains Schultheiss.

    The researchers placed a particular emphasis on the female subjects. They discovered that the hormonal reaction to victory or defeat that occurred in women or female teams was significantly dependent on their personal thirst for power. Women with a particularly marked thirst for power had higher levels of the sex hormones testosterone and estradiol after a victory than after a defeat. This reaction was not recorded in women who a less pronounced power-orientated outlook. This hormonal reaction is the reason why dominant behaviour in women is intensified by a victory and subdued by a defeat.