Chapter 16. Psychopathology: Biological Basis of Behavior Disorders

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By Lydia Denworth A macaque monkey sat in front of a computer. A yellow square—the target—appeared in the periphery on the left side of the screen. After a few seconds delay, a second target appeared on the right. The question was: Which target would the monkey look at first? So far so routine as neuroscience experiments go, but the next step was unusual. By non-invasively directing bursts of inaudible acoustic energy at a specific visual area of the brain, a team of scientists steered the animal’s responses. If they focused on the left side of the brain, the monkey looked to the right more often. If they focused on the right side, the monkey looked to the left more often. The results of the experiment, which were presented last week at the annual Society for Neuroscience meeting, marked the first time that focused ultrasound was safely and effectively used in a nonhuman primate to alter brain activity rather than destroy tissue. A second study, in sheep, had similar results. “The finding paves the way to noninvasive stimulation of specific brain regions in humans,” says Jan Kubanek, a neural engineer at Stanford University School of Medicine and lead author of the macaque study. The technology might ultimately be used to diagnose or treat neurological diseases and disorders like Parkinson’s disease, epilepsy, addiction and depression. Other scientists are optimistic. “The idea that, with a very carefully designed dose, you could actually deliver [focused ultrasound] and stimulate the brain in the place you want and modulate a circuit rather than damage it, is a really important proof of principle,” said Helen Mayberg, MD, of Emory University School of Medicine, who was not involved with the study. © 2017 Scientific American

Keyword: Parkinsons; Depression
Link ID: 24384 - Posted: 12.01.2017

By NICHOLAS BAKALAR The daughters of women exposed to childhood trauma are at increased risk for serious psychiatric disorders, a new study concludes. Researchers studied 46,877 Finnish children who were evacuated to Sweden during World War II, between 1940 and 1944. They tracked the health of their 93,391 male and female offspring born from 1950 to 2010. The study, in JAMA Psychiatry, found that female children of mothers who had been evacuated to Sweden were twice as likely to be hospitalized for a psychiatric illness as their female cousins who had not been evacuated, and more than four times as likely to have depression or bipolar disorder. But there was no effect among male children, and no effect among children of either sex born to fathers who had been evacuated. The most obvious explanation would be that girls inherited their mental illness from their mothers, but the researchers controlled for parental psychiatric disorder and the finding still held. The lead author, Torsten Santavirta, an associate professor of economics at Uppsala University, said that it is possible that traumatic events cause changes in gene expression that can then be inherited, but the researchers did not have access to genetic information. “The most important takeaway is that childhood trauma can be passed on to offspring,” Dr. Santavirta said, “and the wrinkle here is that these associations are sex-specific.” © 2017 The New York Times Company

Keyword: Stress; Epigenetics
Link ID: 24377 - Posted: 11.30.2017

By R. Douglas Fields While examining brain tissue through a microscope of hospital patients in the 1930’s, Hungarian neuropathologist Ladislaus Meduna made an intriguing observation: Brain cells, called glia, increased greatly in tissue taken from people with epilepsy. But samples from patients with schizophrenia and depression had far fewer glia in the cerebral cortex than normal. Unlike neurons, glia cannot fire electrical impulses, so they were (and still are) largely ignored by most neuroscientists. But Meduna speculated that schizophrenia and depression might result from a deficiency of glial cells, so he reasoned that by inducing a seizure, he could increase their numbers and cure his patients. On January 23, 1934, he induced a violent seizure in a man who was hopelessly catatonic from schizophrenia by injecting a chemical, camphor, into the man’s bloodstream. The injection induced an explosive seizure that wracked the man’s body for a full minute. Meduna’s legs gave out in shock after he saw what he had done. The scientist collapsed and two nurses had to help him back to his apartment to recover. Undeterred, Meduna four days later induced another seizure in the same man—who for four years had never spoken or moved and who had been fed continuously through a tube. By the fifth seizure he induced on February 10, 1934, the man awoke, dressed himself, requested breakfast and greeted Meduna cheerfully by name. “I hear them talking that you were going to make some crazy experiment? Did you do it?” he asked This success inspired others: Ugo Cerletti and Lucio Bini in Italy used electricity to induce a seizure by applying electrodes they had obtained from a pig slaughterhouse to the head of one of their mental patients on April 11, 1938. Did the patient get better? In some cases, patients who underwent these primitive procedures experienced improved mental states noticeably. But they could also induce violent, whole-body contractions that sometimes dislocated joints and broke bones. © 2017 Scientific American

Keyword: Depression
Link ID: 24373 - Posted: 11.28.2017

By Claudia Wallis American parents have been warning teenagers about the dangers of marijuana for about 100 years. Teenagers have been ignoring them for just as long. As I write this, a couple of kids are smoking weed in the woods just yards from my office window and about a block and a half from the local high school. They started in around 9 A.M., just in time for class. Exaggerating the perils of cannabis—the risks of brain damage, addiction, psychosis—has not helped. Any whiff of Reefer Madness hyperbole is perfectly calibrated to trigger an adolescent's instinctive skepticism for whatever an adult suggests. And the unvarnished facts are scary enough. We know that being high impairs attention, memory and learning. Some of today's stronger varieties can make you physically ill and delusional. But whether marijuana can cause lasting damage to the brain is less clear. Advertisement A slew of studies in adults have found that nonusers beat chronic weed smokers on tests of attention, memory, motor skills and verbal abilities, but some of this might be the result of lingering traces of cannabis in the body of users or withdrawal effects from abstaining while taking part in a study. In one hopeful finding, a 2012 meta-analysis found that in 13 studies in which participants had laid off weed for 25 days or more, their performance on cognitive tests did not differ significantly from that of nonusers. © 2017 Scientific American

Keyword: Drug Abuse; Schizophrenia
Link ID: 24370 - Posted: 11.28.2017

Patricia Neighmond As the months grow colder and darker, many people find themselves somewhat sadder and even depressed. Bright light is sometimes used to help treat the symptoms of seasonal affective disorder, or SAD. Researchers are now testing light therapy to see if it also can help treat depression that's part of bipolar disorder. It's unclear how lack of light might cause the winter blues, although some suggest that the dark days affect the production of serotonin in the skin. The idea with light therapy for depression is to replace the sunshine lost with a daily dose of bright white artificial light. (Antidepressants, psychotherapy and Vitamin D help, too, according to the National Institute of Mental Health.) The light box is actually more like a screen, the size of your average desktop computer. Some people call it a "happy box." To test its usefulness in treating bipolar disorder, researchers at the Feinberg School of Medicine, Northwestern University enrolled 46 patients who had at least moderate bipolar depression. Half of participants were assigned to receive bright light therapy. The other half received a dim red placebo light. They also kept taking their regular medication. © 2017 npr

Keyword: Biological Rhythms; Schizophrenia
Link ID: 24368 - Posted: 11.27.2017

By EFFY REDMAN It’s late morning on a balmy September day. I try to summon the will to run from the bench where I’m sitting on Broadway and dive under the massive wheels of one of the trucks roaring past. Which section of my body, I wonder, should I hurl beneath the tires. Where would hurt the least, and soonest erase my suffering. I clutch my cellphone, hating its potential for rescue signals. After nine or 10 trucks pass me by, an unkempt man in his mid-50s sits on the bench beside me, plastic cup of lager in one hand, half-smoked self-rolled cigarette in the other. He looks me up and down and grins. Go away, jerk, I think to myself, shooting him an icy glance. Leave me be. “Are you waiting for a date?” he persists. “What are you doing?” I want to kill him, but my resolve switches. I stand abruptly and head for my apartment, where, I calculate, I have enough medications stored to off myself. I ponder what to say in my suicide note. My phone rings: my mother, responding to the please call me asap message I had texted her. “What’s going on?” she says. It is my mother who insists I call my therapist and my mother who, upon my therapist’s urging, drives me to the emergency room. “Can’t you think about how it’s a beautiful sunny day?” she says once I’ve checked in and changed into a hospital gown and scrubs pants. I tug at the neck of my cotton gown, which chokes no matter how much I loosen the ties. ‘“I just feel utterly hopeless,” I say. The depression is a silent, slow motion tsunami of dark breaking over me. I can’t swim away from it and don’t believe I can survive its natural withdrawal. That’s why I am here. © 2017 The New York Times Company

Keyword: Depression
Link ID: 24367 - Posted: 11.27.2017

By JANE E. BRODY Having recently endured more than a month of post-concussion fatigue, I can’t imagine how people with so-called chronic fatigue syndrome navigate through life with disabling fatigue that seemingly knows no end. Especially those who are erroneously told things like “It’s all in your head,” “Maybe you should see a psychiatrist,” or “You’d have a lot more energy if only you’d get more exercise.” After years of treating the syndrome as a psychological disorder, leading health organizations now recognize that it is a serious, long-term illness possibly caused by a disruption in how the immune system responds to infection or stress. It shares many characteristics with autoimmune diseases like rheumatoid arthritis but without apparent signs of tissue damage. Accordingly, doctors now typically refer to it as myalgic encephalomyelitis, meaning brain and spinal cord inflammation with muscle pain, and in scientific papers it is often written as ME/CFS. At the same time, a major shift is underway as far as how the medical profession is being advised to approach treatment. The longstanding advice to “exercise your way out of it” is now recognized as not only ineffective but counterproductive. It usually only makes matters worse, as even the mildest activity, like brushing your teeth, can lead to a debilitating fatigue, the core symptom of the disease. Both the Centers for Disease Control and Prevention in the United States and the National Institute for Health and Care Excellence in Britain are formulating revised guidelines for managing an ailment characterized by six or more months — and sometimes years — of incapacitating fatigue, joint pain and cognitive problems. This new thinking is long overdue. It is understandably difficult for doctors to appreciate that a disorder lacking obvious physical abnormalities could have a physical basis, especially when patients debilitated by a chronic disease that no one understands are likely to be depressed and anxious. © 2017 The New York Times Company

Keyword: Depression
Link ID: 24364 - Posted: 11.27.2017

By Nathaniel Morris Depression afflicts an estimated 16 million Americans every year, many of whom go to their doctors in despair, embarking on an often stressful process about what to do next. These visits may entail filling out forms with screening questions about symptoms such as mood changes and difficulty sleeping. Doctors may ask patients to share intimate details about such issues as marital conflicts and suicidal urges. Some patients may be referred to mental-health specialists for further examination. Once diagnosed with depression, patients frequently face the question: “Are you interested in therapy, medications or both?” As a resident physician in psychiatry, I’ve seen many patients grapple with this question; the most frequent answer I’ve heard from patients is “I’m not sure.” Deciding between different types of medical treatment can be challenging, especially amid the fog of depression. Moreover, patients rely on doctors to help guide them, and we’re often not sure ourselves which is the best approach for a specific patient. People commonly associate psychotherapy with Freud and couches, but newer, evidence-based treatments such as cognitive behavioral therapy have become prominent in the field. CBT helps patients develop strategies to address harmful thoughts, emotions and behaviors that may contribute to depression. There are many proposed explanations for how specific psychotherapies treat depression. These possibilities include giving patients social support and teaching coping skills, and researchers are using neuroimaging to study how these treatments affect depressed patients’ brains. © 1996-2017 The Washington Post

Keyword: Depression
Link ID: 24362 - Posted: 11.26.2017

By Erin Blakemore Jennifer Brea wasn’t supposed to break down. But in 2011, her body did just that. The 28-year-old was on the verge of a Harvard PhD and a wedding, but a series of viral infections transformed her from an energetic young woman to a bedridden patient with a mystery illness. Desperate to escape the pain, exhaustion and loss of muscle control that bound her to her bed, Brea visited a long list of medical specialists — many of whom questioned whether she was sick at all. In reality, Brea has myalgic encephalomyelitis, or ME. Also known as chronic fatigue syndrome, the condition can mystify health-care providers and disable patients. According to the Centers for Disease Control and Prevention, up to 2.5 million Americans suffer from the illness, 90 percent of them undiagnosed. “Unrest,” Brea’s intensely personal documentary about her journey through ME, asks why physicians still know so little about the disease. The film delves into Brea’s ordeal, her marriage and the lives of others whose health was stolen by a condition that can strip a person of dignity, mobility and hope for the future. More women have ME than men, and Brea’s experience fighting for recognition from her doctors is central to the film’s narrative. Her documentary is a testimony not just to the terrors of ME but also to the struggles that women often face when relaying information about their own bodies to medical providers. ME can keep patients painfully separate from their everyday lives and loved ones. “Unrest” breaks through a bit of that isolation and offers a sometimes heartbreaking look at what it takes to survive a poorly understood disease. © 1996-2017 The Washington Post

Keyword: Depression
Link ID: 24360 - Posted: 11.26.2017

Sara Reardon Brain implants that deliver electrical pulses tuned to a person’s feelings and behaviour are being tested in people for the first time. Two teams funded by the US military’s research arm, the Defense Advanced Research Projects Agency (DARPA), have begun preliminary trials of ‘closed-loop’ brain implants that use algorithms to detect patterns associated with mood disorders. These devices can shock the brain back to a healthy state without input from a physician. The work, presented last week at the Society for Neuroscience (SfN) meeting in Washington DC, could eventually provide a way to treat severe mental illnesses that resist current therapies. It also raises thorny ethical concerns, not least because the technique could give researchers a degree of access to a person’s inner feelings in real time. The general approach — using a brain implant to deliver electric pulses that alter neural activity — is known as deep-brain stimulation. It is used to treat movement disorders such as Parkinson’s disease, but has been less successful when tested against mood disorders. Early evidence suggested that constant stimulation of certain brain regions could ease chronic depression, but a major study involving 90 people with depression found no improvement after a year of treatment.1 The scientists behind the DARPA-funded projects say that their work might succeed where earlier attempts failed, because they have designed their brain implants specifically to treat mental illness — and to switch on only when needed. “We’ve learned a lot about the limitations of our current technology,” says Edward Chang, a neuroscientist at the University of California, San Francisco (UCSF), who is leading one of the projects. © 2017 Macmillan Publishers Limited

Keyword: Depression; Robotics
Link ID: 24354 - Posted: 11.24.2017

By Philippa Roxby Confronting an avatar on a computer screen helped patients hearing voices to cope better with hallucinations, a UK trial has found. Patients who received this therapy became less distressed and heard voices less often compared with those who had counselling instead. Experts said the therapy could add an important new approach to treating schizophrenia hallucinations. The trial, on 150 people, is published in The Lancet Psychiatry journal. It follows a much smaller pilot study in 2013. Hallucinations are common in people with schizophrenia and can be threatening and insulting. One in four patients continues to experience voices despite being treated with drugs and cognitive behavioural therapy. In this study, run by King's College London and University College London, 75 patients who had continued to hear voices for more than a year, were given six sessions of avatar therapy while another 75 received the same amount of counselling. In the avatar sessions, patients created a computer simulation to represent the voice they heard and wanted to control, including how it sounded and how it might look. Image copyright King's College London Image caption Three avatars created by people taking part in the therapy The therapist then voiced the avatar while also speaking as themselves in a three-way conversation to help the patient gain the upper hand. Prof Tom Craig, study author from King's College London, said getting patients to learn to stand up to the avatar was found to be safe, easy to deliver and twice as effective as counselling at reducing how often voices were heard. "After 12 weeks there was dramatic improvement compared to the other therapy," he said. "With a talking head, patients are learning to confront and get replies from it. "This shifts the idea that the voice is all-controlling," he said. © 2017 BBC.

Keyword: Schizophrenia
Link ID: 24349 - Posted: 11.24.2017

Sara Reardon When it comes to lab mice and antidepressants, it's complicated. Mouse experiments with the popular club drug ketamine may be skewed by the sex of the researcher performing them, a study suggests. The findings, presented on 14 November at the Society for Neuroscience (SfN) meeting in Washington DC, only deepen the mystery of how ketamine, which has powerful mood-lifting properties, interacts with the brain. They also raise questions about the reproducibility of behavioural experiments in mice. Ketamine is best known as a psychoactive recreational drug. But it has caught psychiatrists’ interest because of its potential to treat depression within hours. It’s unclear exactly how the drug works, however, and many researchers are using animal models to suss out the mechanism. Polymnia Georgiou, a neuroscientist at the University of Maryland in Baltimore, is one of them. In 2015, a male colleague asked her to run some experiments for him while he was out of town, including a standard way of testing antidepressants called the forced-swim test. In this assay, researchers inject healthy mice with a drug, place them into a tank of water and measure how long they swim before they give up and wait for someone to rescue them. Antidepressants can cause healthy mice to swim for longer than their untreated counterparts, which is what Georgiou’s male colleague found during his experiments using ketamine. © 2017 Macmillan Publishers Limited

Keyword: Sexual Behavior; Depression
Link ID: 24341 - Posted: 11.20.2017

By Jennifer Couzin-Frankel Rachel Loewy was an undergraduate in 1995 when she answered a flyer seeking students to assist with a research study. A couple of floors up in a psychology department building, Loewy sat, clipboard in hand, interviewing teenagers whose brain health was beginning to falter. Some heard whispers. Others imagined that their teachers could read their minds, or that fellow students stared at them and wished them harm as they walked down the halls. The teenagers had been diagnosed with schizotypal personality disorder, a condition that can precede schizophrenia. Among the most debilitating and stigmatized psychiatric diseases, schizophrenia can rob sufferers of their self and their future, often in early adulthood. Although these teens didn't have schizophrenia, the researchers believed that some would later deteriorate and be diagnosed with the disorder. But when Loewy met them they were lucid and self-aware. And they were frightened that their mind sometimes spun out of control. Doctors routinely assess a patient's risk of heart attack, various cancers, and diabetes, often intervening to slow or stop disease before it strikes. But preventing psychiatric conditions, from anxiety to depression to schizophrenia, has received scant attention. © 2017 American Association for the Advancement of Science

Keyword: Schizophrenia
Link ID: 24336 - Posted: 11.17.2017

Patricia Neighmond A study published Tuesday in the journal Clinical Psychological Science finds that increased time spent with popular electronic devices — whether a computer, cell phone or tablet — might have contributed to an uptick in symptoms of depression and suicidal thoughts over the last several years among teens, especially among girls. Though San Diego State University psychologist Jean Twenge, who led the study, agrees this sort of research can only establish a correlation between long hours of daily screen time and symptoms of alienation — it can't prove one causes the other — she thinks the findings should be a warning to parents. "One hour, maybe two hours [a day], doesn't increase risk all that much," Twenge says. "But once you get to three hours — and especially four and then, really, five hours and beyond — that's where there's much more significant risk of suicide attempts, thinking about suicide and major depression." Twenge and her colleagues took a hard look at national surveys that asked more than a half million young people, ages 13 to 18, questions that get at symptoms of depression. Twenge says the surveys asked students to respond to statements such as "Life often feels meaningless," or "I feel I can't do anything right," or "I feel my life is not very useful. Between 2010 and 2015 Twenge found the number of teens who answered "yes" to three or more of these questions increased significantly, from 16 percent in 2010 to 22 percent in 2015. © 2017 npr

Keyword: Depression
Link ID: 24327 - Posted: 11.15.2017

By Elly Vintiadis The prevailing wisdom today is that addiction is a disease. This is the main line of the medical model of mental disorders with which the National Institute on Drug Abuse (NIDA) is aligned: addiction is a chronic and relapsing brain disease in which drug use becomes involuntary despite its negative consequences. The idea here is, roughly, that addiction is a disease because drug use changes the brain and, as a result of these changes, drug use becomes compulsive, beyond the voluntary control of the user. In other words, the addict has no choice and his behavior is resistant to long term change. This way of viewing addiction has its benefits: if addiction is a disease then addicts are not to blame for their plight, and this ought to help alleviate stigma and to open the way for better treatment and more funding for research on addiction. This is the main rationale of a recent piece in the New York Times, which describes addiction as a disease that is plaguing the U.S. and stresses the importance of talking openly about addiction in order to shift people’s understanding of it. And it seems like a welcome change from the blame attributed by the moral model of addiction, according to which addiction is a choice and, thus, a moral failing—addicts are nothing more than weak people who make bad choices and stick with them. Yet, though there are positive aspects to seeing addiction in this light, it seems unduly pessimistic and, though no one will deny that every behavior has neural correlates and that addiction changes the brain, this is not the same as saying that, therefore, addiction is pathological and irreversible. And there are reasons to question whether this is, in fact, the case. © 2017 Scientific American

Keyword: Drug Abuse
Link ID: 24307 - Posted: 11.09.2017

Hannah Devlin Science correspondent British scientists have begun testing a radically new approach to treating schizophrenia based on emerging evidence that it could be a disease of the immune system. The first patient, a 33-year old man who developed schizophrenia after moving to London from Cameroon a decade ago, was treated at King’s College Hospital in London on Thursday, marking the start of one of the most ambitious trials to date on the biology of the illness and how to treat it. During the next two years, 30 patients will receive monthly infusions of an antibody drug currently used to treat multiple sclerosis (MS), which the team hopes will target the root causes of schizophrenia in a far more fundamental way than current therapies. The trial builds on more than a decade’s work by Oliver Howes, a professor of molecular psychiatry at the MRC London Institute of Medical Sciences and a consultant psychiatrist at the Maudsley Hospital in south London. Howes’s team is one of several worldwide to have uncovered evidence that abnormalities in immune activity in the brain may lie at the heart of the illness – for some patients, at least. “In the past, we’ve always thought of the mind and the body being separate, but it’s just not like that,” said Howes. “The mind and body interact constantly and the immune system is no different. It’s about changing the way we think about mental illnesses.” Recent work by Howes and colleagues found that in the earliest stages of schizophrenia, people experience a surge in the number and activity of immune cells in the brain. As well as fighting infection, these cells, called microglia, have a “gardening” role, pruning unwanted connections between neurons. But in schizophrenia patients, the pruning appears to become more aggressive, leading to vital connections being lost. © 2017 Guardian News and Media Limited

Keyword: Schizophrenia; Neuroimmunology
Link ID: 24293 - Posted: 11.04.2017

Hannah Devlin Descartes’s notion of dualism – that the mind and body are separate entities – is wrong, but has proved surprisingly persistent, and until recently dominated attempts to understand mental illness. When the brain stopped working properly, a psychological origin was sought. Undoubtedly, life’s experiences and our personalities shape the way our brains function. But there is now a compelling body of evidence that brain disorders can also originate from things going awry in our basic biology. Particularly intriguing is the discovery that the brain, once thought to be separated from the immune system by the blood-brain barrier, is powerfully influenced by immune activity. The latest trial, focused on schizophrenia, is backed by converging evidence from several fields that immune cells in the brain, called microglia, play at least some role in this disease. Prof Oliver Howes, the psychiatrist leading the work, discovered that these cells appear to go into overdrive in the early stages of schizophrenia. Genetics studies have linked changes in immune system genes to increased risk for schizophrenia and anecdotal evidence, including a recent case report of a patient who developed schizophrenia after receiving a bone marrow transplant from a sibling with the illness, also triangulates on to the immune system. “It’s all challenging the idea that the brain is this separate privileged organ,” said Howes. © 2017 Guardian News and Media Limited

Keyword: Schizophrenia
Link ID: 24292 - Posted: 11.04.2017

By Emily Underwood In 2003, neurologist Helen Mayberg of Emory University in Atlanta began to test a bold, experimental treatment for people with severe depression, which involved implanting metal electrodes deep in the brain in a region called area 25. The initial data were promising; eventually, they convinced a device company, St. Jude Medical in Saint Paul, to sponsor a 200-person clinical trial dubbed BROADEN. This month, however, Lancet Psychiatry reported the first published data on the trial’s failure. The study stopped recruiting participants in 2012, after a 6-month study in 90 people failed to show statistically significant improvements between those receiving active stimulation and a control group, in which the device was implanted but switched off. Although that decision was “game over” for BROADEN, the story wasn’t finished for some 44 patients who asked to keep the implants in their brains, and the clinicians responsible for their long-term care, Mayberg explained last week to colleagues at a meeting on the ethical dilemmas of brain stimulation research at the National Institutes of Health (NIH) in Bethesda, Maryland. The episode highlights a tricky dilemma for companies and research teams involved in deep brain stimulation (DBS) research: If trial participants want to keep their implants, who will take responsibility—and pay—for their ongoing care? And participants in last week’s meeting said it underscores the need for the growing corps of DBS researchers to think long-term about their planned studies. © 2017 American Association for the Advancement of Science.

Keyword: Depression
Link ID: 24276 - Posted: 11.01.2017

Sara Reardon Human genome databases are enabling researchers to take a deeper dive into the evolution of psychiatric disorders. Psychiatric disorders can be debilitating and often involve a genetic component, yet, evolution hasn’t weeded them out. Now, recent work is beginning to reveal the role of natural selection — offering a peek at how the genetic underpinnings of mental illness has changed over time. Many psychiatric disorders are polygenic: they can involve hundreds or thousands of genes and DNA mutations. It can be difficult to track how so many genetic regions evolved, and such studies require large genome data sets. But the advent of massive human genome databases is enabling researchers to look for possible connections between mental illnesses and the environmental and societal conditions that might have driven their emergence and development. Others are looking to Neanderthal genetic sequences to help inform the picture of these disorders, as well as cognitive abilities, in humans. Several of these teams presented their findings at the American Society of Human Genetics (ASHG) meeting in Orlando, Florida, in late October. One project found that evolution selected for DNA variants thought to protect against schizophrenia. The study, led by population geneticist Barbara Stranger of the University of Chicago in Illinois, looked at hundreds of thousands of human genomes using a statistical method that identified signals of selection over the past 2,000 years1. There were no signs of selection in genetic regions associated with any other mental illness. Many of schizophrenia's symptoms, such as auditory hallucinations and jumbling sentences, involve brain regions tied to speech, says Bernard Crespi, an evolutionary biologist at Simon Fraser University in Burnaby, Canada. Over the course of hominid evolution, he says, the ability to speak could have outweighed the small, but unavoidable risk that the genes involved in language could malfunction and result in schizophrenia in a small percentage of the population. © 2017 Macmillan Publishers Limited

Keyword: Schizophrenia; Depression
Link ID: 24270 - Posted: 10.31.2017

Jon Hamilton People who are thinking about killing themselves appear to have distinctive brain activity that can now be measured by a computer. In these people, words like "death" and "trouble" produce a distinctive "neural signature" not found in others, scientists report in the journal Nature Human Behavior. More than 44,000 people commit suicide in the U.S. each year. "There really is a difference in the way [suicidal] people think about certain concepts," says Marcel Just, an author of the paper and the D. O. Hebb professor of cognitive neuroscience at Carnegie Mellon University. That difference allowed a computer program to distinguish people who thought about suicide from people who did not more than 90 percent of the time. It also allowed the computer program to distinguish people who had attempted suicide from people who had only thought about it. The results come from a study of just 34 young adults and will need to be replicated, says Barry Horwitz, chief of brain imaging and modeling at the National Institute on Deafness and Other Communication Disorders. But he says they hint at a future in which brain scans and computers can help assess a person's mental health. Horwitz was not involved in the study. "Just looking at behavior is probably inadequate for a lot of purposes," he says. "It's much better to be able to see what the brain is doing." © 2017 npr

Keyword: Depression
Link ID: 24269 - Posted: 10.31.2017