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Green neighborhoods may reduce childhood obesity

First study to look at effect of greenness on inner city children's weight over time

San Diego, October 28, 2008 – Childhood obesity can lead to type 2 diabetes, asthma, hypertension, sleep apnea and emotional distress. Obese children and youth are likely to be obese as adults, experience more cardiovascular disease, high blood pressure and stroke and incur higher healthcare costs. In an article published in the December 2008 issue of the American Journal of Preventive Medicine, researchers report that children living in inner city neighborhoods with higher "greenness" experienced lower weight gains compared to those in areas with less green space.

Researchers from the University of Washington, Indiana University-Purdue University and Indiana University School of Medicine followed more than 3800 children, predominantly African-American and poor, aged 3-16 over a two-year period. Using satellite imaging data to measure vegetation coverage, the investigators found that higher greenness was significantly associated with lower body mass index (BMI) changes in those children. In previous studies of adults, residential density tended to predict physical activity levels, with highly urban environments leading to more walking, less driving and lower BMI. The current study did not find this correlation for children.

Children and youth in urban environments may be active in a wider variety of open spaces (e.g., yards, parks, vacant lots) and less likely to constrain activity to streets and sidewalks. Greenness might indicate proximity to parks, playfields or other open spaces that promote either physical activity or increased time spent outdoors in active play.

Writing in the article, Janice F. Bell, PhD, MPH, Assistant Professor in the department of Health Services at the School of Public Health and Community Medicine, University of Washington, Seattle, and co-investigators state, "This study's findings align with previous research linking exposure to green landscapes with health improvements. Among adults, greenness is associated with less stress and lower BMI, improved self-reported health and shorter post-operative recovery periods. Among children and youth, the positive health effects of green landscapes include improved cognitive functioning and reduced attention deficit hyperactivity disorder symptoms. Ideally, future research in this area will be multidisciplinary – involving city planners, architects, geographers, psychologists and public health researchers – and will consider the ways children live and play in urban environments."

In a commentary published in the same issue of the American Journal of Preventive Medicine, Nick Wareham, MBBS, PhD, of the Institute of Metabolic Science, Cambridge, England, writes, "Previous research on factors associated with physical activity in children has used mostly cross-sectional designs and few prospective studies have been published. In addition, studies have focused mostly on individual biological or psychological factors, with little emphasis, until recently, on collective determinants such as the physical environment. By focusing on environmental determinants in a longitudinal study in children, the study by Bell et al makes an important contribution to the existing literature."

http://www.eurekalert.org/pub_releases/2008-10/ehs-gnm102608.php

UK teen suicide rates on the decline

Research news from the Journal of Child Psychology and Psychiatry

Suicide rates in those aged 10-19 in the UK declined by 28% in the seven year period from 1997-2003, shows a study published today in The Journal of Child Psychology and Psychiatry. The study, carried out by researchers at the University of Manchester, showed that the decline was particularly marked in young males, where rates declined by 35%.

Despite the decline, however, suicide remains more common among young males than young females. For every one adolescent female (aged 15-19 years) who commits suicide in the UK, there are three adolescent males, the study revealed.

The research, which was carried out as part of the National Confidential Inquiry into Suicide and Homicide by People with Mental Illness, showed that there were 1,722 adolescent and juvenile deaths by suicide in the UK between 1997 and 2003, which represents 4% of all suicides in that time period. The majority of young people were aged 15-19 (93% of the sample), and overall, the most common methods of suicide were hanging, followed by self-poisoning.

"Between 1997 and 2003, we found that suicide rates fell significantly, although we can only speculate on what factors may have contributed to the decline," said Dr Kirsten Windfuhr, from the Centre for Suicide Prevention at the University of Manchester. "Although changes to antidepressant prescribing may have been one factor contributing to changing suicide rates, it is likely that a combination of factors, both clinical and socio-economic, will have contributed to the decrease in suicide rates. Suicide is a rare event, and is, thankfully, rarer still among children and adolescents. However, it is still one of the leading causes of death among young people and continued monitoring of recent suicide trends is important."

Over the seven year period, only 14% of young people who committed suicide were in contact with mental health services in the year prior to their death, compared to 26% in adults. Again, there was a marked difference between males and females, with 20% of young females in contact with mental health services compared to only 12% of young males.

"The low rate of service contact in young males is particularly interesting. Young men currently have the highest rates of suicide in the UK, and yet they are least likely to seek help," said Windfuhr. "Further research is needed to identify the specific risk factors associated with young suicide, and a multi-agency approach including health, social and education services may be the most effective strategy for preventing suicide in young people. In particular, research should be focused on the barriers which prevent young males from seeking help."

Wiley-Blackwell

Genes may make some people more prone to anxiety

Carriers of a common gene variation startled more dramatically in response to unpleasant pictures

Inborn differences may help explain why trauma gives some people bad memories and others the nightmare of post-traumatic stress. Scientists in Germany and the United States have reported evidence linking genes to anxious behavior. The findings appear in the August issue of Behavioral Neuroscience, published by the American Psychological Association.

By showing that people who carry a common variation of a gene that regulates the neurotransmitter dopamine have an exaggerated "startle" reflex when viewing unpleasant pictures, the researchers offer a biochemical explanation for why some people find it harder to regulate emotional arousal. Their sensitivity may, in combination with other hereditary and environmental factors, make them more prone to anxiety disorders.

Researchers including Martin Reuter, PhD, of the University of Bonn, Germany, recruited 96 women averaging 22 years old from the Giessen Gene Brain Behavior Project, which investigates biomolecular causes of individual differences in behavior.

The researchers first determined which participants carried which variations (alleles) of the COMT gene, which encodes an enzyme that breaks down dopamine, weakening its signal. (COMT stands for a catabolic enzyme named catechol-O-methyltransferase.) Scientists call its two alleles Val158 and Met158. Depending on ethnicity, more or less half the population carries one copy of each. The rest of the population is roughly divided between carrying two copies of Val158 and two copies of Met158.

Using a well-validated psychophysiological measure, the researchers next measured the intensity of each participant's startle response by attaching electrodes to the eye muscles that, upon emotional arousal, contract and cause a blink. Participants then viewed pictures that were emotionally pleasant (such as animals or babies), neutral (such as a power outlet or hairdryer), or aversive (such as weapons or injured victims at a crime scene) -- 12 pictures of each type for six seconds each. A loud, 35-millisecond white noise, called a startle probe, sounded at random while they watched. When participants blinked, showing the startle response, a bioamplifier took readings from the electrodes and sent the information to a computer for analysis.

People carrying two copies of the Met158 allele of the COMT gene showed a significantly stronger startle reflex in the unpleasant-picture condition than did carriers of either two copies of Val158 allele or one copy of each. The two-Met carriers also disclosed greater anxiety on a standard personality test.

This finding confirms that specific variations in the gene that regulates dopamine signaling may play a role in negative emotionality. The authors speculated that the Met158 allele may raise levels of circulating dopamine in the brain's limbic system, a set of structures that support (among other things) memory, emotional arousal and attention. The researchers said that more dopamine in the prefrontal cortex could result in an "inflexible attentional focus" on unpleasant stimuli, meaning that Met158 carriers can't tear themselves away from something that's arousing -- even if it's bad.

The Met158 allele was created by a relatively recent mutation and only in the evolution of human beings. Other primate species such as chimpanzees carry only the Val/Val genotype. Co-author Christian Montag, Dipl. Psych., observes that for humans, wariness may have been adaptive. He points out, "It was an advantage to be more anxious in a dangerous environment."

A single gene variation, says Montag, can explain only a small portion of variation in anxious behavior – otherwise, in theory, up to half the population could be anxious.

"This single gene variation is potentially only one of many factors influencing such a complex trait as anxiety," he says. "Still, to identify the first candidates for genes associated with an anxiety-prone personality is a step in the right direction."

Although a great deal more research is needed, Montag says that if this line of research bears fruit, one day "it might be possible to prescribe the right dose of the right drug, relative to genetic makeup, to treat anxiety disorders."

Source American Psychological Association

Women end up less happy than men

Less able to achieve their life goals, women end up unhappier than men later in life – even though they start out happier, reveals new research by Anke Plagnol of the University of Cambridge, and University of Southern California economist Richard Easterlin.

Plagnol and Easterlin's study, forthcoming in the Journal of Happiness Studies, is the first to use nationally representative data spanning several decades to examine the role of unfulfilled desires in a person's sense of well-being.

As the researchers explain, expectations of success may vary among those raised in different generations (i.e., an economic depression). Data sets from a range of time periods may also have different demographic compositions.

In their analysis, the researchers control for birth cohort and demographic characteristics such as race and education. They find that women are, on average, happier than men in early adulthood – but the glow wears off with time. Specifically, after the age of 48, men's overall happiness exceeds women's happiness.

These gender patterns of overall happiness correlate to patterns in two significant aspects of life satisfaction: family and finances.

As Plagnol explains: In later life it is "men [who] come closer to fulfilling their aspirations, are more satisfied with their family lives and financial situations, and are the happier of the two."

Women and men have fairly similar life goals when it comes to love, the study reveals. Nine out of 10 people of both genders reach adult life wanting a happy marriage.

"Differences between men and women in aspirations for marriage and children are fairly small," says Plagnol, who received her Ph.D. from USC in 2007. "Gender differences in satisfaction depend largely on attainment."

The saddest period of the average man's life – his 20s – is also the period when he is most likely to be single.

Young men are also more dissatisfied than young women with their financial situations, not because they are worse off, but because they want more and therefore experience a greater "shortfall," the researchers explain.

But age alters many things, including men's money woes and lackluster love lives.

After 34, men are more likely to be married than women, and the gap only widens with age, mirroring men's growing satisfaction with family life.

Men also become more satisfied with their financial situations over time, as reflected in their increased spending power. The researchers found that men tend to covet big-ticket items that might not be within reach until later in life, such as a car or vacation home.

(A notable exception: women want more "nice clothes" than men, the researchers found.)

These findings are consistent with an earlier study by Easterlin showing that recent generations are less satisfied than previous generations, despite having more.

"Of course, one doesn't have to be married to be happy, but if that's something you really want – and it is for most people – then the failure to attain it can have an impact on your overall happiness," Plagnol says, adding that those in a relationship also tend to be in a stronger financial position than those who must depend solely on their own resources.

Some age milestones:

41: Age at which men's financial satisfaction exceeds women's financial satisfaction
48: Age at which men's overall happiness exceeds women's overall happiness
64: Age at which men's satisfaction with family life exceeds women's satisfaction

With thanks to the University of Southern California

The kids most likely to go armed

A new analysis of a 2005 survey of American schoolchildren has identified factors that may be used to help improve school safety. The research, published in BioMed Central's open access journal Annals of General Psychiatry, gives detailed information about the carrying of guns, blades and clubs.

13,707 students participated in the study, 6,664 (50.5%) were male and 7,193 (49.5%) were females. Overall, 10.2% of males and 2.6% of females reported carrying a weapon on school property. An estimated 29.8% of males and 19.3% of females had carried weapons elsewhere.

The analysis was carried out by Emmanuel Rudatsikira, from the Loma Linda University, California, and his colleagues. They showed that the variables most associated with the carrying of weapons were being male and being a member of certain self-selected racial groups. Pupils who identified themselves as white were more likely to carry weapons than those who identified themselves as black.

The authors point out that, "We do not believe that there are any inherent genetic differences that determine race and that affect the way that adolescents behave. We take the view that racial categorization has facilitated the distribution of social and economic resources (housing, school districts, wealth, social networks) that may consequently influence adolescent behaviors and perceptions toward violent behavior".

The results were surprising. The authors state that as the poor are likely to live in violent neighbourhoods, they would be more likely to feel unsafe and therefore carry weapons to school, "We would have expected that minorities such as African Americans, being largely disadvantaged in the United States, would be more likely to bear weapons." Rudatsikira suggests some explanations for this apparent discrepancy "If black students felt less threatened at school, it's less likely they'll carry weapons. Alternatively, the schools they attend may be more vigilant in policing weapon carrying as a possible result of high violence and weapon bearing in black neighbourhoods."

Other factors associated with weapon carrying were substance use, depression, having been a victim of theft or property damage at school, having been raped, having been threatened with a weapon or having been involved in a physical fight.

Serious school failure turns out to be a real bummer for girls, but not boys

Adolescent girls who had a serious school failure by the 12th grade – being expelled, suspended or dropping out – were significantly more likely to have suffered a serious bout of depression at the age of 21 than girls who did not have these problems.

New research published this week in the Journal of Adolescent Health showed that girls who had early conduct problems in elementary school also were at increased risk for depression in early adulthood. However, the University of Washington study did not show any link for boys between academic, behavior or social problems and depression at age 21.

"For girls there are broader implications of school failure," said Carolyn McCarty, a UW research associate professor of pediatrics and lead author of the study. "We already know that it leads to more poverty, higher rates of being on public assistance and lower rates of job stability. And now this study shows it is having mental health implications for girls."

The study showed that girls who were expelled from school were more than twice as likely to suffer depression – 44 percent compared to 20 percent of girls who were not expelled. Thirty-three percent of the girls who dropped out of school later became depressed compared to 19 percent who were not dropouts. Twenty-eight percent of the girls who were suspended later suffered depression versus 19 percent of girls who weren't suspended.

Overall, 45 percent of the girls and 68 percent of the boys in the study experienced a major school failure, but McCarty said these rates were not surprising since the participants in the study came from high-crime neighborhoods. However, the depression rate was higher among girls, 22 percent versus 17 percent for the boys.

"This gender paradox shows that while school failure is more atypical for girls it appears to have more severe consequences when it does occur," said McCarty. "One reason may be that school failure stigmatizes girls more strongly or is harder for them to overcome. We do know that girls with conduct problems, such as school failure, tend to have long-term problems with cascading effects."

She said the study's overall gender rates of depression are comparable to previous studies, although the 17 percent rate for boys was somewhat high.

Data for the study was drawn from the UW's ongoing Seattle Social Development Research Project that was launched in 1985 and has been tracking 808 people since they were in the fifth grade. Students were drawn from 18 Seattle schools in high-crime neighborhoods to study the development of positive and antisocial behaviors. Participants were almost equally divided by gender and identified themselves as white (46 percent), black (24 percent), Asian-American (21 percent), Native American (6 percent) and other groups (3 percent).

McCarty said the study points to the need for communities to create integrated prevention programs to help children deal with academic, social and behavioral problems.

"When adolescents have these kinds of problems and experiences, the response tends to be focused purely on the academic, in part because the school and mental health systems are distinct. We need to look more broadly at functioning and see what is going on with other aspects of their lives including the psychological. We can't just put a Band-Aid on one thing that seems to be a problem because often there is an underlying bigger issue that has to be addressed," she said.

"When school failure emerges we should have remedies and be ready to intervene at that point to prevent later depression" said McCarty, who is directing a middle school study that is evaluating early prevention efforts to thwart depression. "Social and emotional skills are vital to adolescents and they may or may not be taught by schools and their parents. We need to have school-based prevention programs available before problems get much bigger and harder to resolve."

When Fish Talk, Scientists Listen

MBL Visiting Investigators Explore the Evolution of Social Communication

MBL, WOODS HOLE, MA—A male midshipman, a close relative of the toadfish, doesn’t need good looks to attract a mate – just a nice voice. After building a nest for his potential partner, he calls to nearby females by contracting his swim bladder, the air-filled sac fish use to maintain buoyancy. The sound he makes is not a song or a whistle, but a hum; more reminiscent of a long-winded foghorn than a ballad. Female midshipman find it very alluring, and they only approach a male’s nest if he makes this call.

In a paper published this week in Science, three Marine Biological Laboratory (MBL) visiting investigators show that the sophisticated neural circuitry that midshipman use to vocalize develops in a similar region of the central nervous system as the circuitry that allows a human to laugh or a frog to croak, evidence that the ability to make and respond to sound is an ancient part of the vertebrate success story. The research is presented by Andrew Bass of Cornell University, Edwin Gilland of Howard University College of Medicine, and Robert Baker of New York University Medical Center.

“Fish have all the same parts of the brain that you do,” says Bass, the paper’s lead author. The way our brains work is also similar. Just as we have neurons that coordinate when our larynx and tongue change shape to produce words, toadfish and midshipman orchestrate the movement of muscles attached to their swim bladder to produce grunts and hums.

Using larval toadfish and midshipman, the group traced the development of the connection from the animal’s vocal muscles to a cluster of neurons located in a compartment between the back of its brain and the front of its spinal cord. The same part of the brain in more complex vertebrates, such as humans, has a similar function, indicating that it was highly selected for during the course of evolution.

Scientists have known for decades that these fish make sounds, but they are not the only species whose hums, growls, and grunts have meaning. “There’s reason to suggest that the use of sound in social communication is widespread among fishes,” Bass says.

This research is an example of the growing field of evolutionary neurobiology, which aims to understand the evolution of behavior through neurobiology. According to Bass, fish are an incredibly successful group, making up nearly half of the living species of vertebrates, and vocal communication may be partly responsible. “The kind of work we’re doing contributes to answering questions as to why these animals are so successful,” Bass says. “We’re only touching the tip of the iceberg here.”

The majority of this research was completed at the MBL over the past five years, although the question of how fish communicate through sound first came to Bass as a graduate student studying the neurobiology of fish at the University of Michigan. In the summer of 1986, Bass, then a summer instructor at the MBL, met Robert Baker, who was also researching the neurobiology of fish calling. For years they discussed fish social behavior with the roots of the hypothesis tested in the Science paper first published in 1997 and the research to test that hypothesis beginning in 2003. “The whole project began at the MBL,” Bass says. “It’s where collaborations happen.”

Source

Bullying-suicide link explored in new study by researchers at Yale

Researchers at Yale School of Medicine have found signs of an apparent connection between bullying, being bullied and suicide in children, according to a new review of studies from 13 countries published in the International Journal of Adolescent Medicine and Health.

"While there is no definitive evidence that bullying makes kids more likely to kill themselves, now that we see there's a likely association, we can act on it and try to prevent it," said review lead author Young-Shin Kim, M.D., assistant professor at Yale School of Medicine's Child Study Center.

In the review, Kim and colleague Bennett Leventhal, M.D., analyzed 37 studies that examined bullying and suicide among children and adolescents. The studies took place in the United States, Canada, several European countries (including the United Kingdom and Germany), South Korea, Japan and South Africa.

Almost all of the studies found connections between being bullied and suicidal thoughts among children. Five reported that bullying victims were two to nine times more likely to report suicidal thoughts than other children were.

Not just the victims were in danger: "The perpetrators who are the bullies also have an increased risk for suicidal behaviors," Kim said.

However, the way the studies were designed made it impossible for researchers to determine conclusively whether bullying leads to suicide, Kim said. In addition, the authors report that most of the studies failed to take into account the influence of factors like gender, psychiatric problems and a history of suicide attempts.

Kim said her interest in bullying grew several years ago when she visited South Korea and heard several new slang terms referring to bullies and their victims. The words reflected "an elaborated system of bullying," she said.

According to international studies, bullying is common and affects anywhere from 9 percent to 54 percent of children. In the United States, many have blamed bullying for spurring acts of violence, including the Columbine High School massacre.

In the United States, many adults scoff at bullying and say, "Oh, that's what happens when kids are growing up," according to Kim, who argues that bullying is serious and causes major problems for children.

Kim is currently studying whether being bullied actually leads to suicide, although she acknowledges it will be difficult for researchers to get a firm grasp on a cause-and-effect relationship. She said that to confirm a definitive link, researchers would have to rule out the possibility that some unknown factor makes certain children more susceptible to both bullying and suicide.

For now, Kim said, the existing research should encourage adults to pay more attention to bullying and signs of suicidal behavior in children. "When we see kids who are targets of bullying, we should ask them if they're thinking about hurting themselves," she said. "We should evaluate and prevent these things from happening."

With thanks to Yale University