Chapter 4. The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
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By Laura Sanders To drive a rat to drink, make it smoke first. Rats dependent on nicotine escalate their drinking more quickly than rats that haven’t been exposed to nicotine, researchers report in the April 15 Journal of Neuroscience. The results help explain why alcohol and tobacco addictions in people often go hand in hand. After nicotine injections, rats that had previously been exposed to alcohol dosed themselves with more alcohol than rats unexposed to nicotine did. Scientists were able to curb this booziness: Rats injected with a compound that made brain cells ignore nicotine did not boost their intake of alcohol. The double whammy of nicotine and alcohol dependence may be due to a select group of nerve cells throughout the rat brain that respond to this nicotine-aided drinking, Olivier George of the Scripps Research Institute in La Jolla, Calif., and colleagues found. If a similar response happens in humans, studying these particular nerve cells might ultimately lead to better ways to curb both alcohol and tobacco dependencies, the researchers write. R. Leão et al. Chronic nicotine activates stress/reward-related brain regions and facilitates the transition to compulsive alcohol drinking. Journal of Neuroscience. Vol. 35, April 15, 2015. doi:10.1523/JNEUROSCI.3302-14.2015. © Society for Science & the Public 2000 - 2015.
Keyword: Drug Abuse
Link ID: 20799 - Posted: 04.15.2015
By Lenny Bernstein Children with two of the most severe forms of epilepsy can suffer scores of seizures each day, as well as long-term physical and cognitive problems. The two conditions, Dravet and Lennox-Gastaut syndromes, are quite rare but unfortunately very resistant to treatment with current epilepsy drugs. Now a compound found in marijuana plants has shown promising results in a preliminary study, during which it sharply reduced the number of seizures suffered by these children. Some were even seizure-free after three months of taking the drug, cannabidiol, the research showed. "We're very encouraged by the data," said Orrin Devinsky, director of the NYU Langone Comprehensive Epilepsy Center and leader of the research. A more rigorous study of cannabidiol's impact has begun and will help determine how effective it really is, he said. In making cannabidiol, the marijuana plant's psychoactive material (THC) was removed. A 99 percent pure liquid version of the drug was given for three to six months to 137 people with the two syndromes. Most were children (the subjects ranged in age from 2 to 26), and before the experiment they suffered a disturbing average of 95.3 convulsive seizures every month. Convulsive seizures are the more severe, violent kind; people with epilepsy can experience a wide variety of seizures, including some mild enough that they appear to be merely staring into space for a few seconds. Some of the subjects had taken as many as 10 different epilepsy drugs, with little success.
by Bethany Brookshire In 2011, a group of scientists “turned mice gay.” The only issue is, of course, they didn’t. Rather, Yi Rao and colleagues at Peking University in Beijing, China, showed that male mice will cheerfully mount both male and female mice, as long as their brains are deficient in one chemical messenger: serotonin. The paper, published in Nature, received plenty of media coverage. Now, two other research groups report seemingly opposite findings: Male mice with no serotonin in their brains still prefer female mice to males. The researchers contend that serotonin is about social communication and impulsive behaviors, not sex. Mounting behavior aside, sexual preference in mice is not about “turning mice gay.” It never has been. Instead, it’s about the role that a single chemical can play in animal behavior. And it’s about what, exactly, those behaviors really mean. Serotonin serves as a messenger between cells. It plays important roles in mood. Serotonin-related drugs are used to treat some forms of migraine. And of course, serotonin plays a role in the psychedelic effects of recreational drugs such as hallucinogens. So when the Peking University group set out to show serotonin’s role in sexual preference, they attacked it from several angles. They used mice that had been genetically engineered to lack the brain cells that usually produce serotonin. They used a chemical to deplete serotonin in the brains of normal mice. And they created another strain of mice that lacked the enzyme that makes serotonin in the brain. © Society for Science & the Public 2000 - 2015
Keyword: Sexual Behavior
Link ID: 20787 - Posted: 04.11.2015
Leana Wen Every doctor and nurse in our hospital's emergency room knew Jerome. He was one of our regulars. In his 20s, he had back problems that led him to become addicted to prescription painkillers. That habit proved too expensive, and he switched to heroin. Jerome used to come to the ER nearly every week. Often, he just wanted a sandwich and someone to talk to. He had lost his job and his home. Several months ago, he decided he had to quit heroin. We helped him with health insurance so that he could find a primary care doctor. Our social worker connected him with addiction treatment, including medications and mental health counseling. He was also working on rekindling a relationship with his estranged family. One day, paramedics brought Jerome to the ER. They had found him in an abandoned building. He'd relapsed and was shooting heroin. A friend saw him unconscious and called for help. By the time paramedics arrived, he wasn't breathing and his heart had stopped beating. In the ER, we tried to resuscitate him for nearly an hour. We weren't successful. In Baltimore, where I serve as health commissioner, more people die from drug and alcohol overdoses than from homicide. In 2013, there were 246 deaths related to drugs and alcohol, compared with 235 homicides. © 2015 NPR
Keyword: Drug Abuse
Link ID: 20783 - Posted: 04.11.2015
Do Alcoholics Anonymous participants do better at abstinence than nonparticipants because they are more motivated? Or is it because of something inherent in the A.A. program? How researchers answered these questions in a recent study offers insight into challenges of evidence-based medicine and evidence-informed policy. The study, published in the journal Alcoholism: Clinical and Experimental Research, teased apart a treatment effect (improvement due to A.A. itself) and a selection effect (driven by the type of people who seek help). The investigators found that there is a genuine A.A. treatment effect. Going to an additional two A.A. meetings per week produced at least three more days of alcohol abstinence per month. Separating treatment from selection effects is a longstanding problem in social and medical science. Their entanglement is one of the fundamental ways in which evidence of correlation fails to be a sign of causation. For many years, researchers and clinicians have debated whether the association of A.A. with greater abstinence was caused by treatment or a correlation that arises from the type of people who seek it. Such confounding is often addressed with an experiment in which individuals are randomly assigned to either a treatment or a nontreatment (or control) group in order to remove the possibility of self-selection. The treatment effect is calculated by comparing outcomes obtained by participants in each group. Several studies of A.A. have applied this approach. For instance, Kimberly Walitzer, Kurt Dermen and Christopher Barrick randomized alcoholics to receive treatment that strongly encouraged and supported A.A. participation or a control group. The former exhibited a greater degree of abstinence. In an ideal randomized controlled trial (R.C.T.), everyone selected for treatment receives it and no one in the control group does. The difference in outcomes is the treatment effect, free of bias from selection. That’s the ideal. However, in practice, randomized controlled trials can still suffer selection problems. © 2015 The New York Times Company
Keyword: Drug Abuse
Link ID: 20767 - Posted: 04.08.2015
Arran Frood A psychedelic drink used for centuries in healing ceremonies is now attracting the attention of biomedical scientists as a possible treatment for depression. Researchers from Brazil last month published results from the first clinical test of a potential therapeutic benefit for ayahuasca, a South American plant-based brew1. Although the study included just six volunteers and no placebo group, the scientists say that the drink began to reduce depression in patients within hours, and the effect was still present after three weeks. They are now conducting larger studies that they hope will shore up their findings. The work forms part of a renaissance in studying the potential therapeutic benefits of psychedelic or recreational drugs — research that was largely banned or restricted worldwide half a century ago. Ketamine, which is used medically as an anaesthetic, has shown promise as a fast-acting antidepressant; psilocybin, a hallucinogen found in ‘magic mushrooms’, can help to alleviate anxiety in patients with advanced-stage cancer2; MDMA (ecstasy) can alleviate post-traumatic stress disorder; and patients who experience debilitating cluster headaches have reported that LSD eases their symptoms. Ayahuasca, a sacramental drink traditionally brewed from the bark of a jungle vine (Banisteriopsis caapi) and the leaves of a shrub (Psychotria viridis), contains ingredients that are illegal in most countries. But a booming ayahuasca industry has developed in South America, where its religious use is allowed, and where thousands of people each year head to rainforest retreats to sample its intense psychedelic insights. © 2015 Nature Publishing Group,
by Bethany Brookshire A new round of dietary do’s and don’ts accompanied last month’s scientific report on the latest food research, summarizing everything from aspartame to saturated fats. The report puts eggs back on the menu. High dietary cholesterol is no longer linked to blood cholesterol in most healthy people. But what grabbed the headlines? Coffee, of course. Many of us are happy to raise a mug to our legal stimulant of choice, especially with the report’s suggestion that three to five cups of joe get a pass. But where do these numbers come from? What science do nutrition experts take into account to determine whether coffee is harmful or safe? And — perhaps the most important question — what does “three to five cups” really mean? The good news for coffee comes from the 2015 Dietary Guidelines Advisory Committee, a group of experts in nutrition and health appointed by the Department of Health and Human Services and the U.S. Department of Agriculture to review the science behind what Americans should eat. The report, released February 19, is not the be-all-end-all of what should be on our plates and in our cups. Instead, it’s a scientific report intended to help the HHS and USDA make policy decisions for the next edition of the Dietary Guidelines for Americans, due out later this year. This is the first time the U.S. Dietary Guidelines have addressed coffee at all. But now, there is enough science on coffee to make a closer look worthwhile, says Tom Brenna, a food scientist at Cornell University and a member of the Committee. “There was so much evidence out there,” he says. “Instead of just five or six papers on the subject, there’s a huge number.” © Society for Science & the Public 2000 - 2015
Keyword: Drug Abuse
Link ID: 20758 - Posted: 04.06.2015
By Shereen Lehman (Reuters Health) - Children exposed to tobacco smoke at home are up to three times more likely to have attention deficit hyperactive disorder (ADHD) as unexposed kids, according to a new study from Spain. The association was stronger for kids with one or more hours of secondhand smoke exposure every day, the authors found. And the results held when researchers accounted for parents' mental health and other factors. "We showed a significant and substantial dose-response association between (secondhand smoke) exposure in the home and a higher frequency of global mental problems," the authors write in Tobacco Control, online March 25. According to the Centers for Disease Control and Prevention, two of every five children in the US are exposed to secondhand smoke regularly. Alicia Padron of the University of Miami Miller School of Medicine in Florida and colleagues in Spain analyzed data from the 2011 to 2012 Spanish National Health Interview Survey, in which parents of 2,357 children ages four to 12 reported the amount of time their children were exposed to secondhand smoke every day. The parents also filled out questionnaires designed to evaluate their children's mental health. According to the results, about eight percent of the kids had a probable mental disorder. About 7% of the kids were exposed to secondhand smoke for less than one hour per day, and 4.5% were exposed for an hour or more each day. © 2015 Scientific American,
Founded by two men in Akron, Ohio, in 1935, Alcoholics Anonymous has since spread around the world as a leading community-based method of overcoming alcohol dependence and abuse. Many people swear by the 12-step method, which has become the basis of programs to treat the abuse of drugs, gambling, eating disorders and other compulsive behaviors. But not everyone's a fan. In a recent critique of AA, author Gabrielle Glaser writes in the April issue of The Atlantic that, "Nowhere in the field of medicine is treatment less grounded in modern science." Glaser, whose 2013 book, Her Best-Kept Secret, explores what she calls "the epidemic of female drinking" in the U.S., says recent research on the brain suggests that the abstinence advocated by AA isn't the only solution — or even the best for many people. Cognitive therapy combined with the medication naltrexone, Glaser says, can help ease cravings and has been shown in some studies to help some problem drinkers learn to drink moderately without quitting. Glaser's magazine story has drawn fire from defenders of AA, including Huffington Post writer Tommy Rosen, who calls himself "a person in long-term recovery (23 years) who overcame severe drug addiction and alcoholism in great part due to the 12 Steps." Glaser's article, Rosen writes, is "painfully one-sided." Therapist and psychology reporter Robi Ludwig told Glaser and the host of MSNBC's program All in With Chris Hayes last week that she thinks it's "very dangerous to put out the idea that AA doesn't work. Does it work for everybody? No. There's not going to be one form of treatment that works for everybody." © 2015 NPR
Keyword: Drug Abuse
Link ID: 20729 - Posted: 03.28.2015
Claudia Dreifus Twenty-three states and the District of Columbia have legalized medical marijuana, but scientific research into its appropriate uses has lagged. Dr. Mark Ware would like to change that. Dr. Ware, 50, is the director of the Canadian Consortium for the Investigation of Cannabinoids and the director of clinical research of the Alan Edwards Pain Management Unit of McGill University Health Center. Medical marijuana has been legal in Canada for 16 years, and Dr. Ware, a practicing physician, studies how his patients take the drug and under what conditions it is effective. We spoke for two hours at the recent meeting of the American Association for the Advancement of Science and later by telephone. Our interviews have been condensed and edited for space. Q. How did you become interested in the medical possibilities of cannabis? A. In the late 1990s, I was working in Kingston, Jamaica, at a clinic treating people with sickle cell anemia. My British father and Guyanese mother had raised me in Jamaica, and I’d attended medical school there. One day, an elderly Rastafarian came for his annual checkup. I asked him, “What are your choices of medicines?” He leaned over the table and said, “You must study the herb.” That night, I went back to my office and looked up “cannabis and pain.” What I found were countless anecdotes from patients who’d obtained marijuana either legally or not and who claimed good effect with a variety of pain-related conditions. There were also the eye-opening studies showing that the nervous system had specific receptors for cannabinoids and that these receptors were located in areas related to pain. Everything ended with, “More studies are needed.” So I thought, “This is what I should be doing; let’s go!” © 2015 The New York Times Company
By Brian Handwerk In the U.S., legal hurdles have long hampered research into marijuana. But as more states approve medical and even recreational marijuana, scientific inquiries have spiked, especially studies aimed at finding out what exactly is in today's weed—and what it does to our bodies. In Colorado, which made marijuana legal in November 2012, the latest results show that the pot lining store shelves is much more potent than the weed of 30 years ago. But the boost in power comes at a cost—modern marijuana mostly lacks the components touted as beneficial by medical marijuana advocates, and it is often contaminated with fungi, pesticides and heavy metals. “There's a stereotype, a hippy kind of mentality, that leads people to assume that growers are using natural cultivation methods and growing organically," says Andy LaFrate, founder of Charas Scientific, one of eight Colorado labs certified to test cannabis. "That's not necessarily the case at all." LaFrate presented his results this week at a meeting of the American Chemical Society (ACS) in Denver. LaFrate says he's been surprised at just how strong most of today's marijuana has become. His group has tested more than 600 strains of marijuana from dozens of producers. Potency tests, the only ones Colorado currently requires, looked at tetrahydrocannabinol (THC), the psychoactive compound that produces the plant's famous high. They found that modern weed contains THC levels of 18 to 30 percent—double to triple the levels that were common in buds from the 1980s. That's because growers have cross-bred plants over the years to create more powerful strains, which today tout colorful names like Bruce Banner, Skunkberry and Blue Cookies.
Keyword: Drug Abuse
Link ID: 20712 - Posted: 03.24.2015
By Camilla Turner It is one of life’s most enduring mysteries. A question that music, poetry, myth and legend has, for thousands of years, tried but failed to answer. However, we may now be a step closer to discovering what love is, thanks to a scientific study that has obtained the first empirical evidence of love-related alterations in the brain. A team of researchers from universities in China and New York used MRI scans to track the physical effects of love on the brain and has pieced together a “love map” of the human mind. The study found that several areas of the brain showed increased activity in those who were in love, including in the parts of the brain linked to reward and motivation. The researchers said their results shed light on the “underlying mechanisms of romantic love” and would pave the way for a brain scan that could act as a “love test”. Scientists recruited 100 students from Southwest University in Chongqing, China, who were divided into three groups according to their relationship status: an “in-love” group, comprised of those who were in love at the time; an “ended-love” group, who had recently ended loving relationships; and a “single” group, who had never been in love. Participants were told not to think of anything while their brains were scanned, so that researchers could monitor the differences between the brains of students in all three groups. © Copyright of Telegraph Media Group Limited 2015
Keyword: Sexual Behavior
Link ID: 20692 - Posted: 03.17.2015
By John Horgan In 1990 The New York Times published a front-page article by Lawrence Altman, a reporter with a medical degree, announcing that scientists had discovered “a link between alcoholism and a specific gene.” The evidence for the "feel-good gene," which supposedly reduces anxiety, is flimsy, just like the evidence linking specific genes to high intelligence, violent aggression, homosexuality, bipolar disorder and countless other complex human traits and ailments. That was merely one in a string of reports in which the Times and other major media hyped what turned out to be erroneous claims linking complex traits and disorders—from homosexuality and high intelligence to schizophrenia and bipolar disorder—to specific genes. I thought those days were over, and that scientists and the media have learned to doubt extremely reductionist genetic accounts of complex traits and behaviors. I was wrong. Last Sunday, the “Opinion” section of the Times published an essay, “The Feel-Good Gene,” which states: “For the first time, scientists have demonstrated that a genetic variation in the brain makes some people inherently less anxious, and more able to forget fearful and unpleasant experiences. This lucky genetic mutation produces higher levels of anandamide–the so-called bliss molecule and our natural marijuana–in our brains. In short, some people are prone to be less anxious simply because they won the genetic sweepstakes and randomly got a genetic mutation that has nothing at all to do with strength of character.” This article, like the one touting the alcoholism gene 25 years ago, was written by a physician, Richard Friedman, professor of psychiatry at Weill Cornell Medical College. I emphasize this fact because scientific hype is often blamed on supposedly ignorant journalists like me rather than on physicians and other so-called experts. © 2015 Scientific American
By Maggie Fox Teenagers who use marijuana heavily grow up to have poor memories and also have brain abnormalities, a new study shows. The study cannot say which came first — the brain structure differences or the pot use. But it suggests there could be long-term effects of heavy marijuana use. A team at Northwestern University looked at 97 volunteers with and without mental illness. The dope smokers said they'd used marijuana daily starting at age 16 or 17, and said they had not used other drugs. The daily marijuana users had an abnormally shaped hippocampus and performed about 18 percent more poorly on long-term memory tasks, the researchers reported in the journal Hippocampus. The hippocampus is a part of the brain used in storing long-term memory. "The memory processes that appear to be affected by cannabis are ones that we use every day to solve common problems and to sustain our relationships with friends and family," said Dr. John Csernansky, who worked on the study. Previous research by the same Northwestern team showed heavy pot smokers had poor short-term and working memory and abnormally shaped brain structures including the striatum, globus pallidus and thalamus. "It is possible that the abnormal brain structures reveal a pre-existing vulnerability to marijuana abuse," Matthew Smith, who led the study, said in a statement.
|By Anne Skomorowsky On a Saturday night last month, 12 students at Wesleyan University in Connecticut were poisoned by “Molly,” a hallucinogenic drug they had taken to enhance a campus party. Ambulances and helicopters transported the stricken to nearby hospitals, some in critical condition. Molly—the street name for the amphetamine MDMA—can cause extremely high fevers, liver failure, muscle breakdown, and cardiac arrest. Given the risks associated with Molly, why would anybody take it? The obvious answer—to get high—is only partly true. Like many drugs of abuse, Molly causes euphoria. But Molly is remarkable for its “prosocial” effects. Molly makes users feel friendly, loving, and strongly connected to one another. Molly is most commonly used in settings where communion with others is highly valued, such as raves, music festivals, and college parties. Recently, psychiatrists have taken an interest in its potential to enhance psychotherapy; this has led to new research into the mechanisms by which MDMA makes people feel closer. It appears that MDMA works by shifting the user’s attention towards positive experiences while minimizing the impact of negative feelings. To investigate this, a 2012 study by Cedric Hysek and colleagues used the Reading the Mind in the Eyes Test (RMET), which was developed to evaluate people with autism. In the RMET, participants are shown 36 pictures of the eye region of faces. Their task is to describe what the person in the picture is feeling. Volunteers taking MDMA, under carefully controlled conditions, improved in their recognition of positive emotions; but their performance in recognizing negative emotions declined. In other words, they incorrectly attributed positive or neutral feelings to images that were actually negative in emotional tone. They mistook negative and threat-related images for friendly ones. © 2015 Scientific American
Keyword: Drug Abuse
Link ID: 20678 - Posted: 03.12.2015
By RICHARD A. FRIEDMAN CHANCES are that everyone on this planet has experienced anxiety, that distinct sense of unease and foreboding. Most of us probably assume that anxiety always has a psychological trigger. Yet clinicians have long known that there are plenty of people who experience anxiety in the absence of any danger or stress and haven’t a clue why they feel distressed. Despite years of psychotherapy, many experience little or no relief. It’s as if they suffer from a mental state that has no psychological origin or meaning, a notion that would seem heretical to many therapists, particularly psychoanalysts. Recent neuroscience research explains why, in part, this may be the case. For the first time, scientists have demonstrated that a genetic variation in the brain makes some people inherently less anxious, and more able to forget fearful and unpleasant experiences. This lucky genetic mutation produces higher levels of anandamide — the so-called bliss molecule and our own natural marijuana — in our brains. In short, some people are prone to be less anxious simply because they won the genetic sweepstakes and randomly got a genetic mutation that has nothing at all to do with strength of character. About 20 percent of adult Americans have this mutation. Those who do may also be less likely to become addicted to marijuana and, possibly, other drugs — presumably because they don’t need the calming effects that marijuana provides. One patient of mine, a man in his late 40s, came to see me because he was depressed and lethargic. He told me at our first meeting that he had been using cannabis almost daily for at least the past 15 years. “It became a way of life,” he explained. “Things are more interesting, and I can tolerate disappointments without getting too upset.” © 2015 The New York Times Company
Hannah Devlin, science correspondent Psychedelic drugs could prove to be highly effective treatments for depression and alcoholism, according to a study which has obtained the first brain scans of people under the influence of LSD. Early results from the trial, involving 20 people, are said to be “very promising” and add to existing evidence that psychoactive drugs could help reverse entrenched patterns of addictive or negative thinking. However, Prof David Nutt, who led the study, warned that patients are missing out on the potential benefits of such treatments due to prohibitive regulations on research into recreational drugs. Speaking at a briefing in London, the government’s former chief drugs adviser, said the restrictions amounted to “the worst censorship in the history of science”. After failing to secure conventional funding to complete the analysis of the latest study on LSD, Nutt and colleagues at Imperial College London, are now attempting to raise £25,000 through the crowd-funding site Walacea.com. “These drugs offer the greatest opportunity we have in mental health,” he said. “There’s little else on the horizon.” There has been a resurgence of medical interest in LSD and psilocybin, the active ingredient in magic mushrooms, after several recent trials produced encouraging results for conditions ranging from depression in cancer patients to post-traumatic stress disorder. © 2015 Guardian News and Media Limited
Zoe Cormier Data from population surveys in the United States challenge public fears that psychedelic drugs such as LSD can lead to psychosis and other mental-health conditions and to increased risk of suicide, two studies have found1, 2. In the first study, clinical psychologists Pål-Ørjan Johansen and Teri Suzanne Krebs, both at the Norwegian University of Science and Technology in Trondheim, scoured data from the US National Survey on Drug Use and Health (NSDUH), an annual random sample of the general population, and analysed answers from more than 135,000 people who took part in surveys from 2008 to 2011. Of those, 14% described themselves as having used at any point in their lives any of the three ‘classic’ psychedelics: LSD, psilocybin (the active ingredient in so-called magic mushrooms) and mescaline (found in the peyote and San Pedro cacti). The researchers found that individuals in this group were not at increased risk of developing 11 indicators of mental-health problems such as schizophrenia, psychosis, depression, anxiety disorders and suicide attempts. Their paper appears in the March issue of the Journal of Psychopharmacology1. The findings are likely to raise eyebrows. Fears that psychedelics can lead to psychosis date to the 1960s, with widespread reports of “acid casualties” in the mainstream news. But Krebs says that because psychotic disorders are relatively prevalent, affecting about one in 50 people, correlations can often be mistaken for causations. “Psychedelics are psychologically intense, and many people will blame anything that happens for the rest of their lives on a psychedelic experience.” © 2015 Nature Publishing Group,
Children who attend school in heavy traffic areas may show slower cognitive development and lower memory test scores, Spanish researchers have found. About 21,000 premature deaths are attributed to air pollution in Canada each year, according to the Canadian Medical Association. The detrimental effects of air pollution on cardiovascular health and on the lungs are well documented and now researchers are looking at its effects on the brain. To that end, Dr. Jordi Sunyer and his colleagues from the Centre for Research in Environmental Epidemiology in Barcelona measured three aspects of memory and attentiveness in more than 2,700 primary school children every three months over 12 months. "What was surprising for us is among our children, we see very robust, consistent effects," Sunyer said Tuesday from Rome. The associations between slower cognitive development and higher levels of air pollutants remained after the researchers took factors such as parents’ education, commuting time, smoking in the home and green spaces at school into account. The researchers measured air pollutants from traffic twice, in the school courtyard and inside the classroom for schools with high and low traffic-related air pollution. Pollutants from burning fossil fuels, carbon, nitrogen dioxide and ultrafine particles were measured. For example, working memory improved 7.4 per cent among children in highly polluted schools compared with 11.5 per cent among those in less polluted schools. ©2015 CBC/Radio-Canada.
Anti-depressants are the most commonly-prescribed medication in the U.S., with one in 10 Americans currently taking pills like Zoloft and Lexapro to treat depression. But these pharmaceuticals are only fully effective roughly 30 percent of the time, and often come with troublesome side effects. In a controversial new paper published in the journal Neuroscience & Biobehavioral Reviews, psychologist Paul Andrews of McMaster University in Ontario argues that this failure of medication may be based in a misunderstanding of the underlying chemistry related to depression. Andrews surveyed 50 years' worth of research supporting the serotonin theory of depression, which suggests that the disease is caused by low levels of the "happiness" neurotransmitter, serotonin. But Andrews argues that depression may actually be caused by elevated levels of serotonin. And this fundamental misunderstanding may be responsible for inappropriate treatment: The most common form of antidepressants are selective serotonin re-uptake inhibitors (SSRIs), which operate by targeting serotonin receptors in the brain in an effort to amplify serotonin production. Currently, scientists are unable to measure precisely how the brain releases and uses serotonin, because it can't be safely observed in a human brain. But Andrews points to research on animals which suggests that serotonin might work just the opposite from what we've assumed. ©2015 TheHuffingtonPost.com, Inc.
Link ID: 20636 - Posted: 03.02.2015