James Morgan It's one of the most fabled talents in the animal world – elephants' ability to "talk" via rumbles in the earth. Now zoologists in Namibia are trying to harness these seismic social calls - to lure rampaging males back to safety. They played the low rumble of a female on heat to bulls in must (a state of sexual readiness), who turned and headed for the vibration source. The tool could help save elephants from Etosha National Park from the risk of violent conflicts with farmers. The trials are being led by Dr Caitlin O'Connell-Rodwell, of Stanford University. She told the American Association for the Advancement of Science conference in Chicago that park rangers are "very excited" about the prospect of using the technique to protect the endangered animals. "The bulls in must were very responsive. We have shown that we can set the elephants on a very specific trajectory," said Dr O'Connell-Rodwell. "At the watering hole, we waited for them to arrive, and then used the calls to set them on one path, and then turn them back round again. "You see the male in the video pressing his trunk against the ground. He's on a mission – he's looking for that female in oestrus," she said. "The response was intense and so directed. We were not expecting such intensity. "We suggest this could be used as a tool by the park rangers – to help the elephants to stay out of trouble. "The Namibian Environment Ministry is very interested," Dr O'Connell-Rodwell added. Elephants are renowned for their ability to detect vibrations through the ground at great distances. These include the mating calls of females who are in oestrus – or on heat, a phase which only occurs every five years. (C)BBC

Keyword: Hearing
Link ID: 12563 - Posted: 06.24.2010

By James Morgan It is the ultimate "gentleman's agreement". Rather than compete for females, male long-tailed manakins co-operate with their friends. The tropical birds pair up to perform a courtship song and dance, but the alpha male gets the girl every time. Meanwhile his "wingman" spends five years playing second fiddle. But he eventually inherits the mating site. The dance, dubbed "backwards leapfrog", was filmed in Costa Rica by zoologists from the University of Wyoming. At first glance, it appears like a competitive "dance-off". But in fact it is a co-operative pact between buddies, says Dr David McDonald, of Wyoming University. "As far as I know it is the only example of male-male [mating] co-operation in the animal kingdom," he told delegates at the American Association for the Advancement of Science (AAAS) meeting in Chicago. "The male birds' partnership lasts up to five years. During that time, the beta male does not copulate. "He has to wait until alpha male dies - he doesn't kick him out. So he may be waiting until he's 10, 15 or even older." The wingman may be equally as good at dancing as the alpha. Nevertheless, he agrees to forego sex and let his buddy take the spoils. In return, he will eventually inherit the mating site and become the alpha himself. The deal could be compared to Gordon Brown and Tony Blair's infamous "Granita pact". At the London restaurant, Brown allegedly agreed to support Blair in his bid for Prime Minister, on condition that he would eventually inherit the reins. "It's a rough life for a beta male manakin," concedes Dr McDonald. "But if he hits the jackpot he is one of the most successful vertebrates on the planet earth." (C)BBC

Keyword: Sexual Behavior; Evolution
Link ID: 12562 - Posted: 02.16.2009

by Linda Geddes Phobias and post-traumatic stress could be banished for good by taking a commonly prescribed drug for blood pressure. Previous studies had suggested that people who experienced traumatic events such as rape and car crashes showed fewer signs of stress when recalling the event if they had first been injected with the beta blocker propranolol, but it was unclear whether the effect would be permanent or not. Fearful memories often return, even after people have been treated for them. To investigate whether propranolol could stop fear returning in the longer term, Merel Kindt and her colleagues at the University of Amsterdam, the Netherlands, conditioned 60 healthy students to associate a picture of a spider with an electric shock, so that they would eventually be startled by the picture even in the absence of a shock. However, if the conditioned students were given oral propranolol before seeing the picture, their startle response was eliminated. What's more, it didn't return when the students were put through a second round of conditioning that should have reinstated their fear – suggesting that the association may have been permanently broken. Those given a placebo pill could eventually be trained not to be startled by the spider picture, by repeatedly showing it to them in the absence of a shock. © Copyright Reed Business Information Ltd

Keyword: Learning & Memory; Emotions
Link ID: 12561 - Posted: 06.24.2010

By Tina Hesman Saey CHICAGO – With all due respect to the old song, a kiss is not just a kiss. Scientists say romantic kissing affects hormones involved in stress and attachment, and may help people determine whether they’ve found “the one.” Researchers discussed the science of smooching at a press conference February 13 at the annual meeting of the American Association for the Advancement of Science. More than 90 percent of human societies practice kissing, says Helen Fisher, an anthropologist at Rutgers University in New Brunswick, N.J. Chimpanzees kiss too. And even those who don’t kiss still have a lot of facial contact with others. This leads Fisher to believe that kissing probably offers some evolutionary advantage. Men tend to prefer wetter, open-mouth kisses with lots of tongue action, Fisher notes. This style of kissing may allow men to transfer more testosterone to their female partners to put the ladies in the mood. The open-mouth kiss may also help the guys figure out where a woman is in her menstrual cycle. “This really is a powerful assessment tool,” Fisher says. “A first kiss can kill a relationship.” Couples that get past the first kiss aren’t done with kissing chemistry, though. Wendy Hill of Lafayette College in Easton, Penn., and her students brought 15 heterosexual couples into the student health center for a kissing experiment. Each of the volunteers drooled into a cup before the experiment began so the researchers could measure levels of the stress hormone cortisol in the saliva samples. Researchers also took blood samples to measure levels of oxytocin, a hormone associated with bonding. © Society for Science & the Public 2000 - 2009

Keyword: Sexual Behavior; Chemical Senses (Smell & Taste)
Link ID: 12560 - Posted: 06.24.2010

Exposure to second-hand smoke may increase the risk of developing dementia, according to a study by British and American researchers. While scientists have long suspected a link between smoking and cognitive impairment, the study is the first large-scale attempt to link second-hand smoke to increased risk for cognitive impairment. In a study in Thursday's online British Medical Journal, researchers with the universities of Cambridge and Michigan tested saliva samples of nearly 5,000 non-smokers over age 50. They were looking for cotinine — a product of nicotine that can be found in saliva for about a day after exposure to smoke. Participants were also assessed for brain function and cognitive impairment. The study found people with the highest cotinine levels had a 44 per cent increased risk of cognitive impairment, compared to people with the lowest cotinine levels. The researchers argue the link between second-hand smoke and cognitive impairment could be explained, given that heart disease increases the risk of developing dementia and second-hand smoke exposure is known to cause heart disease. In an accompanying editorial, Dr. Mark Eisner from the University of California said while the serious negative health effects of second-hand smoke like cancer and premature death have been established beyond doubt, there is still a lot to learn about the scale of illness caused by second-hand smoke. © CBC 2009

Keyword: Drug Abuse; Alzheimers
Link ID: 12559 - Posted: 06.24.2010

By Tina Hesman Saey CHICAGO — An international group of scientists has completed the first rough draft of Neandertal’s genetic instruction manual. The genetic evidence suggests that humans and Neandertals are very similar, but that the two species probably didn’t interbreed. Speaking by video teleconference from Leipzig, Germany, scientists led by Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology announced the achievement to reporters gathered at the annual meeting of the American Association for the Advancement of Science. Pääbo said that the team has decoded 3.7 billion bases of Neandertal DNA from a bone of a female Neandertal fossil discovered in Vindija cave in Croatia. That DNA represents about 63 percent of the total Neandertal genome. “It’s a milestone,” says John Hawks, a paleoanthropologist at the University of Wisconsin–Madison. The announcement was not a surprise, and the team decoding the Neandertal genome has presented updates of its progress and some of its findings at scientific meetings, but Hawks and other scientists are looking forward to the public release of the Neandertal genome data, expected later this year. Analysis of the genome reveals that humans and Neandertals share genetic roots stretching back at least 830,000 years. Neandertals, the species Homo neandertalensis, were humans’ closest relatives, appearing about 300,000 years ago and living in Europe and parts of Asia until going extinct about 30,000 years ago. © Society for Science & the Public 2000 - 2009

Keyword: Evolution; Language
Link ID: 12558 - Posted: 06.24.2010

Music may be the analgesic of the art world. A recent study done at Glasgow Caledonian University found that people who were listening to their favourite music felt less pain and could stand pain for a longer period. Pain researcher Laura Mitchell has measured how people respond to pain with various forms of distractions, including relaxing music, listening to humorous audio tapes, doing math puzzles and looking at art. As she told CBC's Q cultural affairs show, music is the stimulus that most seems to keep people's minds off the pain. "Favourite music has come out consistently, even to an extent that's really surprised me in designing these studies, as being extremely effective in how people can tolerate the pain and in actually reducing how much pain they feel," Mitchell said. But not just any music — it's not the relaxing jazz playing in the dentist's office or the classical piped into the clinic waiting room that does people good, but their own personal favourite. "I've done this now with about … 400 people and there doesn't seem to be anything in common between the pieces that they bring," Mitchell said. © CBC 2009

Keyword: Pain & Touch; Hearing
Link ID: 12557 - Posted: 06.24.2010

By Julie Steenhuysen CHICAGO (Reuters) - Babies who use many gestures to communicate when they are 14 months-old have much larger vocabularies when they start school than those who don't, U.S. researchers said on Thursday. They said babies with wealthier, better-educated parents tend to gesture more and this may help explain why some children from low-income families fare less well in school. "When children enter school, there is a large socioeconomic gap in their vocabularies," said the University of Chicago's Meredith Rowe, whose study appears in the journal Science. Gestures could help explain the difference, Rowe told the American Association for the Advancement of Science annual meeting in Chicago. Vocabulary is a key predictor of school success. Earlier research showed that well-off, educated parents tend to talk to their children more than their poorer, less-educated peers. "What we are doing here is going one step earlier and asking, does this socioeconomic status relate to gesture, and can that explain some of the gap we see at school entry," Rowe said. © 2009 NY Times Co.

Keyword: Language; Development of the Brain
Link ID: 12556 - Posted: 06.24.2010

Employees who are paid to quit smoking may be more successful, say researchers who offered up to $750 US for anyone who butted out for a year. In an experiment at General Electric Co., 15 per cent of study participants were tobacco-free about a year later — three times the success rate of a comparison group who weren't paid to quit smoking cigarettes, researchers report in Thursday's New England Journal of Medicine. "This kind of reward system provides them with direct, positive feedback in the present," rather than delayed, intangible health benefits, said Dr. Kevin Volpp of the University of Pennsylvania School of Medicine, and lead researcher of the study. Previous studies did not find that money helped people not to fall off the wagon, but Volpp said the earlier work included too few participants or too small a financial incentive. "You'd be surprised at what that little incentive does," said Dan Anzalone, 54, who quit smoking cold turkey three years ago next month after a 35-year habit. Although 70 per cent of smokers in the United States say they want to quit, only about two or three per cent per year actually do, the researchers said. Anzalone was among the 878 employees who were randomly assigned to receive information about smoking-cessation programs, and use the company's health plan for doctor visits and quit-smoking aids, or information plus financial incentives. © CBC 2009

Keyword: Drug Abuse
Link ID: 12555 - Posted: 06.24.2010

By PAM BELLUCK Amanda Kitts lost her left arm in a car accident three years ago, but these days she plays football with her 12-year-old son, and changes diapers and bearhugs children at the three Kiddie Cottage day care centers she owns in Knoxville, Tenn. Amanda Kitts lost her arm in a car accident in 2006, but a new kind of prosthetic allows her to tie shoes at her day care center. Ms. Kitts, 40, does this all with a new kind of artificial arm that moves more easily than other devices and that she can control by using only her thoughts. “I’m able to move my hand, wrist and elbow all at the same time,” she said. “You think, and then your muscles move.” Her turnaround is the result of a new procedure that is attracting increasing attention because it allows people to move prosthetic arms more automatically than ever before, simply by using rewired nerves and their brains. The technique, called targeted muscle reinnervation, involves taking the nerves that remain after an arm is amputated and connecting them to another muscle in the body, often in the chest. Electrodes are placed over the chest muscles, acting as antennae. When the person wants to move the arm, the brain sends signals that first contract the chest muscles, which send an electrical signal to the prosthetic arm, instructing it to move. The process requires no more conscious effort than it would for a person who has a natural arm. Copyright 2009 The New York Times Company

Keyword: Robotics
Link ID: 12554 - Posted: 06.24.2010

Scientists have debunked the myth that one in 10 children are illegimate without their legal father's knowledge, saying the real figure is closer to one in 25. They reached their conclusion by examining the Y chromosomes of 1,600 men not thought to be related, with 40 surnames to find out whether there was a link between the chromosome and the surnames, which are handed down to boys through the male line. Some uncommon surnames, such as Attenborough and Herrick, had a clear association with particular genetic markers on the Y chromosome, suggesting that those men sharing such surnames were linked by a distant, male relative. The result allowed the scientists to establish that the probability of illegitimacy among men with the same surname was somewhere between one and four per cent. Professor Mark Jobling of Leicester University, who carried out the study, said: "People often quote a figure of one in 10 for the number of people born illegitimately. Our study shows that this is likely to be an exaggeration. The real figure is more likely to be less than one in 25." While common surnames like Smith and Brown did not show any significant link with the genetic markers of the Y chromosome, less common surnames like Attenborough, Haythornthwaite, Herrick, Stribling and Swindlehurst showed a definite association with the male chromosome. © Copyright of Telegraph Media Group Limited 2009

Keyword: Sexual Behavior
Link ID: 12553 - Posted: 06.24.2010

by Roger Highfield , Richard Wiseman and Rob Jenkins THE history of science could have been so different. When Charles Darwin applied to be the "energetic young man" that Robert Fitzroy, the Beagle's captain, sought as his gentleman companion, he was almost let down by a woeful shortcoming that was as plain as the nose on his face. Fitzroy believed in physiognomy - the idea that you can tell a person's character from their appearance. As Darwin's daughter Henrietta later recalled, Fitzroy had "made up his mind that no man with such a nose could have energy". Fortunately, the rest of Darwin's visage compensated for his sluggardly proboscis: "His brow saved him." The idea that a person's character can be glimpsed in their face dates back to the ancient Greeks. It was most famously popularised in the late 18th century by the Swiss poet Johann Lavater, whose ideas became a talking point in intellectual circles. In Darwin's day, they were more or less taken as given. It was only after the subject became associated with phrenology, which fell into disrepute in the late 19th century, that physiognomy was written off as pseudoscience. Now the field is undergoing something of a revival. Researchers around the world are re-evaluating what we see in a face, investigating whether it can give us a glimpse of someone's personality or even help to shape their destiny. What is emerging is a "new physiognomy" which is more subtle but no less fascinating than its old incarnation. © Copyright Reed Business Information Ltd

Keyword: Miscellaneous
Link ID: 12552 - Posted: 06.24.2010

By Tina Hesman Saey Although it may not be as dramatic as the Big Bang birthing the universe, an explosion of DNA duplication in the common ancestor of humans, chimpanzees and gorillas may be responsible for many of the differences among the species, a new study suggests. The big blowup happened 8 million to 12 million years ago, but its effects are still apparent today. Human and great ape genes are notoriously similar, with few differences in the genetic letters that make up the instruction manual for building each of the primates. But gorillas, orangutans, chimpanzees and humans are obviously different. A new analysis of the entire genomes of humans and their ape cousins, published in the Feb. 11 Nature, suggests the differences may have roots in DNA duplications. Researchers led by Evan Eichler, a Howard Hughes Medical Institute investigator at the University of Washington in Seattle, compared the genomes of macaques, orangutans, gorillas, chimpanzees, bonobos and humans. The scientists found that chunks of the genomes had been copied and rearranged, sometimes multiple times, within each of the lineages. After orangutans branched off the primate family tree, duplication rates accelerated dramatically in the common ancestor of gorillas, chimpanzees and humans.The burst continued in the common ancestor of humans and chimps, but then slowed again. At the same time that duplication rates were heating up, other types of mutation — such as single letters changes in the genetic sequence — slowed down. access © Society for Science & the Public 2000 - 2009

Keyword: Evolution
Link ID: 12551 - Posted: 06.24.2010

by Graham Lawton THEY called it the second summer of love. Twenty years ago, young people all over the world donned T-shirts emblazoned with smiley faces and danced all night, fuelled by a molecule called MDMA. Most of these clubbers have since given up ecstasy and are sliding into middle age. The question is, has ecstasy given up on them? Enough time has finally elapsed to start asking if ecstasy damages health in the long term. According to the biggest review ever undertaken, it causes slight memory difficulties and mild depression, but these rarely translate into problems in the real world. While smaller studies show that some individuals have bigger problems, including weakened immunity and larger memory deficits, so far, for most people, ecstasy seems to be nowhere near as harmful over time as you may have been led to believe. The review was carried out by the UK Advisory Council on the Misuse of Drugs (ACMD), an independent body that advises the UK government on drug policy. As New Scientist went to press the final report had still to be published, but the committee was expected to recommend downgrading MDMA from a class A drug to a class B, putting it on a par with cannabis in terms of harmfulness. Nobody is arguing that taking ecstasy is risk-free: its short-term effects are fairly uncontroversial. MDMA is toxic, though not powerfully so - an average person would need to take around 20 or 30 tablets to reach a lethal dose. And for a small fraction of people, even small amounts of ecstasy can kill. For example, around half a million people take ecstasy every year in England and Wales, and 30 die from the acute effects, mostly overheating or water intoxication. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse
Link ID: 12550 - Posted: 06.24.2010

By Lucas Laursen Before the reels on a slot machine stop spinning, a gambler's brain is already anticipating the potential rewards. And although two bananas on the pay line with a third just barely visible won't pay a gambler any more than three random fruits, such near misses have the well-documented, if irrational, effect of enticing gamblers to try again. The reason, according to a new study, is that these near misses activate the same reward signals in the brain as a win. Slot machine makers capitalize on the near-miss effect. Researchers have found that they program their games to tease players with near misses about 30% of the time--a number previous studies have found optimal for getting gamblers to keep coming back. Games that offer gamblers the option to stop one reel on a favored icon--say a cherry--until the others spin to a stop also tend to inflate gambler's self-confidence. Taking these factors into account, a team led by Luke Clark of the University of Cambridge in the United Kingdrom developed a simplified slot machine game on a computer. The group asked 15 volunteers--mostly male and with an average age of 26--to play the game while it used functional magnetic resonance imaging (fMRI) to scan their brain activity. The subjects could choose when to stop one of two spinning reels on the screen, each decorated with six icons, including a banana, a pair of boots, and an elephant (see picture). They then watched while the second reel stopped spinning. When the icons matched, the volunteers won £0.50 in real money, but when the icon they chose landed just above or below the pay line, they earned no money, and the researchers logged the event as a near miss. In other trials, the computer chose which icon stopped in the first reel. © 2009 American Association for the Advancement of Science

Keyword: Emotions; Drug Abuse
Link ID: 12549 - Posted: 06.24.2010

By Penelope Green There are no dark corners in Madison, Wisconsin, a university town that sparkles with endowment and research dollars—more than $900 million last year—as well as just plain Midwestern niceness. The grants are well earned: It was at the University of Wisconsin–Madison that the first bone marrow transplant was performed and the first synthetic gene was created. It was here that human stem cells were isolated and cultured in a lab for the first time. And for more than a decade, one of the campus's most productive hit makers has been the Laboratory for Affective Neuroscience, run by a 56-year-old neuroscientist and professor of psychology and psychiatry named Richard J. Davidson, PhD, who has been systematically uncovering the architecture of emotion. Davidson, whose youthful appearance and wide-open smile give him more than a passing resemblance to Jerry Seinfeld, has been studying the brain structures behind not just anxiety, depression, and addiction but also happiness, resilience, and, most recently, compassion. Using brain imaging technologies, in particular a device called a functional magnetic resonance imaging (fMRI) machine, a sort of Hubble telescope for the brain, Davidson and his researchers have observed the areas associated with various emotions and how their function changes as an individual moves through them. His "brain maps" have revealed the neural terrain of so-called normal adults and children, as well as those suffering from mood disorders and autism. Davidson has also studied a now rather famous group of subjects: Tibetan monks with years of Buddhist meditation under their gleaming pates. © 2009 Harpo Productions, Inc.

Keyword: Emotions
Link ID: 12548 - Posted: 06.24.2010

By Pat Wingert and Barbara Kantrowitz When Dr. Lauren Streicher, an assistant professor of obstetrics and gynecology at Northwestern University's medical school in Chicago, got a call from "The Oprah Winfrey Show" inviting her to discuss menopausal hormones with actress Suzanne Somers, she figured she'd better read Somers's best-selling books on the subject. As Streicher worked her way through the first chapter, she started underlining every sentence she felt was inaccurate. "But pretty soon, I had to stop," Streicher says, "because I was underlining almost everything."The taping of the show, which aired Jan. 29, proved equally disconcerting. Somers, a self-styled hormone and anti-aging expert whose controversial books promise midlife women that they will feel young and sexy if they take unregulated hormone therapy (HT) in much higher doses and for much longer time periods than most experts recommend, was literally given center stage. She was seated next to Winfrey, the newly proclaimed convert to the so-called bio-identical hormones promoted by the 62-year-old Somers. (Bio-identical generally refers to products that are chemically identical to hormones produced by a woman's body.) While Winfrey, 55, encouraged "every woman" to read Somers's book, the guests with actual medical degrees were relegated to seats in the audience, where they had to sit quietly unless called upon. Interspersed were taped segments of Somers smearing her arms with hormone cream, standing on her head and lining up the 40 dietary supplements she takes with her morning smoothie. The whole setup seemed to give the drugs that Somers uses the same enthusiastic endorsement that turns everything Winfrey promotes into a blockbuster. The resulting spectacle disappointed many doctors who thought Winfrey had higher standards for the quality of medical information she dispersed—or, at least, more of a commitment to balance. Some said they were particularly upset because doctors had complained to Winfrey's production company about what they saw as misinformation disseminated during the show she did on hormone therapy two weeks before that featured Dr. Phil McGraw's wife, Robin. © 2009 Newsweek, Inc.

Keyword: Hormones & Behavior
Link ID: 12547 - Posted: 06.24.2010

By JANE E. BRODY How sweet it is! The American diet, that is. While the current recommendation is a maximum intake of eight teaspoons of sugars a day, one 12-ounce can of regular soda (or a 20-ounce bottle of VitaminWater) delivers eight or nine teaspoons. That means you are at or over the limit before you’ve eaten a single cookie or container of fruit-flavored yogurt, or even some commercial tomato soups or salad dressings with added sugars. The result is an average daily intake of more than 20 teaspoons of sweet calories. Although much fuss has been raised about high-fructose corn syrup, when it comes to calories and weight gain, it makes no difference if the sweetener was derived from corn, sugar cane, beets or fruit juice concentrate. All contain a combination of fructose and glucose and, gram for gram, supply the same number of calories. All contribute to the excessive caloric intake that has resulted in an epidemic of obesity among Americans in the last 25 years. Dr. George Bray, a specialist in obesity and metabolism at the Pennington Biomedical Research Center of Louisiana State University, has calculated that “the current epidemic of obesity could be explained by the consumption of an extra 20-ounce soft drink each day.” Among the most recent substances to take a turn as dietary villain is high-fructose corn syrup, a relatively cheap and reliable sweetener criticized, among other reasons, for being “artificial.” Copyright 2009 The New York Times Company

Keyword: Obesity
Link ID: 12546 - Posted: 06.24.2010

By Coco Ballantyne Giving Alzheimer's patients a battery of cognitive tests may help predict whether it's safe for them (and us) to get behind the wheel, according to a new study. "We found that tests that involved visual perception and visual memory were particularly important in preventing driving errors," says Jeffrey Dawson, a biostatistician at the University of Iowa College of Public Health in Iowa City and lead author of the study published in Neurology. Dawson hopes the findings will pave the way for the creation of a test that physicians could give to people diagnosed with Alzheimer's to determine if it’s safe for them to be on the road. Alzheimer’s disease, the most common form of dementia, affects an estimated five million people in the U.S., according to the Alzheimer's Association, a nonprofit based in Chicago, Illinois. The disease appears to be caused by protein plaques and tangles that accumulate in the brain, damaging cells and chipping away at the victim's cognition and motor skills. Dawson compared the driving ability of 40 men and women ages 51 to 89 with early Alzheimer's to 115 drivers ages 42 to 89 with no signs of dementia. (The average age of the Alzheimer's group, 75, was six years older than that of the other group, but the discrepancy was accounted for in the final statistical analysis, Dawson notes). The researchers gave all drivers a series of tests designed to measure cognitive, visual, and motor skills. He says the Alzheimer's patients did worse in virtually all of them. © 1996-2009 Scientific American Inc.

Keyword: Alzheimers
Link ID: 12545 - Posted: 06.24.2010

By Solmaz Barazesh Mothers with no previous history of mental illness face the greatest risk for postpartum psychosis during the first month after childbirth, a new study suggests. Postpartum depression is a common problem for many women in the days following delivery. But about one in 1,000 new mothers develops postpartum psychosis, a serious mental illness involving delusional thoughts, hallucinations and the inability to distinguish between reality and imagination. The new study found that first-time mothers who suffer postpartum psychosis faced the highest risk in the first month after delivery, and that the problem can strike women who had no previous history of mental illness. In the study, published online February 9 in PLoS Medicine, epidemiologist Unnur Valdimarsdóttir of the Karolinska Institute in Stockholm and colleagues used hospital records to track first-time mothers during the 90 days following childbirth. Of the almost 750,000 women in the study, 892 developed postpartum psychosis, with most cases reported within a month of childbirth. The rapid reduction in hormone levels after childbirth could trigger the psychosis in some women, the authors suggest. Earlier studies show that schizophrenic women face the greatest risk of psychosis when hormone levels are low. Trauma associated with the pregnancy and birth itself could also contribute to postpartum psychosis, Valdimarsdóttir says. © Society for Science & the Public 2000 - 2009

Keyword: Schizophrenia; Hormones & Behavior
Link ID: 12544 - Posted: 06.24.2010