Brain Drain

The brain contains lymphatic vessels similar to those found elsewhere in the body, a mouse study shows.

uring an infection. The brain is considered “immune privileged,” such that when exposed to foreign material, it takes longer to mount an immune response than does the rest of the body. Furthermore, to date, traditional lymphatic vessels had not been found there.

Several nontraditional routes of fluid circulation in the brain have been described, however. In recent years, neuropathologists Roxana Carare and Roy Weller of the University of Southampton, U.K., reported a system by which CSF—produced in the ventricles—exits the brain via the mucous membranes of the nose and by which interstitial fluid (ISF)—solute-bearing liquid filtered from the blood—leaves by traveling along the basement membranes of capillaries and cerebral arteries. In 2012, Maiken Nedergaard of the University of Rochester Medical Center in New York and her colleagues reported that the circulation of CSF and ISF in the brain was facilitated by water channels in the glial cells that abut the brain vasculature, and coined the term “glymphatic system.”

The Kipnis team’s latest finding represents an additional lymphatic pathway for the brain. Working in mice, Kipnis and his colleagues found that vessels expressing markers of lymphatic vessels elsewhere in the body ran along the dural sinuses, drainage lines in the brain that collect outgoing blood and CSF, emptying these fluids into the jugular vein. They also found that the vessels contained immune cells.

Mouse brain top viewWIKIMEDIA, DATABASE CENTER FOR LIFE SCIENCE

The researchers also probed the circulatory pathways of these vessels by injecting mice with two different tracers—one intravenously, to the circulatory system, and one into the subarachnoid space, a fluid-filled space between the inner two meninges. The tracer injected into the brain stained the newly discovered lymphatic vessels, indicating that CSF passes through them, while the intravenous dye stained separate blood vessels.

Further, the researchers injected Evans blue dye into the subarachnoid space and found that it stained the deep, though not the superficial, cervical lymph nodes. Investigating this pathway from the other direction, they sewed together channels of the cervical lymph nodes and found that fluid backed up in the new lymphatic vessels.

Carare, who was not involved in the study, noted that in a previous study led by Weller, tracer injected into the subarachnoid space traveled to the cervical lymph nodes through the nasal route. “The presence of Evans blue in the present study may be a result of a combination of drainage mechanisms and pathways,” she wrote in an e-mail to The Scientist.

CSF drainage through the nasal pathway “may represent a highly specialized system of the dural lymphatics described in this paper,” Carare added.

While much remains to be worked out, Kipnis noted that, at the very least, these latest results add to mounting evidence of immune activity in the healthy brain. “If you go into the literature, 20 years ago, the idea was that if you see immune cells in the brain, something must be going wrong,” he said. “Now we know that we see immune cells in healthy brains. . . . It’s part of normal physiology; it should be there. Immune activity in the brain is not always pathological.”

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Does having more sex make you less happy?

 The suggestion that sex boosts happiness has been made time and time again both in research papers and popular writing on the subject, such as self-help books. Now, a new study from researchers at Carnegie Mellon University in Pittsburgh, PA, goes against conventional wisdom to cast doubt on the theory that the more sex we have, the happier we are.

The researchers believe that the group instructed to have more sex reported lower levels of happiness because the couples were required to have more sex as part of the study, rather than them initiating it naturally.

In 2013, a study published in Social Indicators Researchfound that people reported steadily higher levels of happiness with increasing sexual frequency. And people who believed they were having less sex than their peers reported being less happy than those who believed they were having as much or more sex than their peers.

That study found that people who had sex once a week were 44% more likely to report a higher level of happiness compared with peers who had no sex in the previous year, and people who had sex up to three times a week were 55% more likely to report higher levels of happiness.

While the team behind the 2013 study used national survey data and statistical analyses to arrive at its conclusions, the Carnegie Mellon (CMU) researchers behind the new study recruited 128 healthy, married individuals between the ages of 35 and 65 who were in male-female couples in an attempt to investigate how sexual frequency affects happiness,.

The couples were randomly assigned into either a group that was asked to double the frequency of their weekly sexual intercourse or a group that received no instructions on sexual frequency.

At the start of the study - the results of which are published in the Journal of Economic Behavior & Organization - the participants completed surveys to establish baselines on health behaviors, happiness levels and occurrence, type and pleasure received from sex.

The couples also completed online questionnaires measuring these variables every day during the 3-month experimental period of the study. An exit survey was also completed to compare against the baseline results.

The CMU team found that the couples instructed to have more sex reported a small decrease in happiness, lower sexual desire and decreased enjoyment from sex.

However, the researchers believe that this lowered happiness was not simply caused by having more sex, but by the fact the couples were required to have more sex as part of the study, without them initiating it naturally.

Authors still believe that couples do not have enough sex

George Loewenstein, the study's lead investigator and the Herbert A. Simon University Professor of Economics and Psychology in the Dietrich College of Humanities and Social Sciences, explains:

"Perhaps couples changed the story they told themselves about why they were having sex, from an activity voluntarily engaged in to one that was part of a research study. If we ran the study again, and could afford to do it, we would try to encourage subjects into initiating more sex in ways that put them in a sexy frame of mind, perhaps with babysitting, hotel rooms or Egyptian sheets, rather than directing them to do so."

Interestingly, Prof. Loewenstein believes that the majority of couples have less sex than is good for them and considers increasing sexual frequency to be beneficial for most couples.

"The desire to have sex decreases much more quickly than the enjoyment of sex once it's been initiated," adds Tamar Krishnamurti, a research scientist in CMU's Department of Engineering and Public Policy.

"Instead of focusing on increasing sexual frequency to the levels they experienced at the beginning of a relationship," elaborates Krishnamurti, "couples may want to work on creating an environment that sparks their desire and makes the sex that they do have even more fun."

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9 in 10 people with mental illness report high levels of discrimination

They may have the sun, sea, Hollywood and Disneyland, but in a new study Californians report encountering high levels of discrimination due to psychological stress.

Most respondents felt that recovery from mental illness is possible - more than 70% said they are satisfied with life - and that they would seek treatment for mental illness when needed.

Behavioral scientists at the nonprofit research organization RAND worked with the California Mental Health Services Administration (CalMHSA) to conduct the California Well-Being Survey as an attempt to research and create prevention and early intervention programs to improve the mental health of Californians.

"This new report from RAND researchers highlights both the need to confront stigma, and the opportunity to promote mental health in our state with the statewide stigma reduction efforts offered by CalMHSA," says Wayne Clark, executive director of CalMHSA.

The researchers surveyed 1,066 Californians who had previously reported mild to serious psychological distress in the California Health Interview Survey, which looked at a variety of health issues.

The authors say that the new California Well-Being Survey is the first population-based survey to look at people who are either currently experiencing mental health problems - or are at risk from them - but who may not have received treatment.

Majority of respondents believe the mentally ill face high levels of prejudice

The behavioral scientists found that just 41% of respondents believed that people are caring and sympathetic toward people with mental illnesses, while a huge 81% believed that those with mental illnesses experience high levels of prejudice and discrimination.

More than two thirds of respondents stated that they would definitely or probably hide a mental health problem they were experiencing from co-workers or classmates. More than one third also said they would disguise mental health problems from family and friends.

Nearly 9 in 10 of those who reported having had a mental health problem said they experienced discrimination as a result of it - most often in intimate social relationships, but also in high levels at school or work. Health care providers and law enforcement officials were also alleged to behave in a discriminatory way by the study respondents.

However, despite reporting high levels of discrimination, more than 80% of participants in the survey said they have plans in place for them to stay or become well and continue to meet personal goals.

Overall, most participants felt that recovery from mental illness is possible - more than 70% said they are satisfied with life - and that they would seek treatment for mental illness when it is needed.

One third of people in the survey said that during the previous 12 months they had been reached by CalMHSA's early intervention efforts, and 90% reported engaging with other activities related to CalMHSA campaigns during the past year.

"This survey shows that CalMHSA's partnership of California's counties is successfully reaching the population most at risk for mental health challenges to increase support and encourage help-seeking," Clark says.

RAND's Eunice Wong, lead author of the report, says that although Californians facing a mental health challenge are displaying resilience in their own attitudes to mental health, stigma remains:

"While California residents facing mental health challenges are finding ways to cope and maintain important aspects of well-being, they are substantially burdened by self-stigma and discrimination, which may significantly undermine recovery. Our overall findings show a clear need for stigma and discrimination reduction efforts in California."

The study is part of RAND's evaluation of mental health initiatives funded by California's Proposition 63 - a tax on millionaires residing in The Golden State - that are designed to reduce stigma and discrimination around mental illness and prevent suicides.

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Mindfulness and antidepressants offer 'similar level of protection' against depression

Mindfulness-based cognitive therapy offers a similar level of protection against relapses of depression to antidepressants, according to the results of a new trial published in The Lancet.

Mindfulness-based cognitive therapy works by teaching people the skills to identify and respond constructively to thoughts and feelings linked with depression.

"Depression is a recurrent disorder. Without ongoing treatment, as many as 4 out of 5 people with depression relapse at some point," says lead author Willem Kuyken, professor of clinical psychology at the University of Oxford in the UK.

Antidepressants are currently the key maintenance treatment for preventing relapse - studies report that antidepressants reduce the likelihood of relapse by up to two thirds when taken correctly.

"However," says study co-author Prof. Richard Byng, from the Plymouth University Peninsula Schools of Medicine and Dentistry in the UK, "there are many people who, for a number of different reasons, are unable to keep on a course of medication for depression. Moreover, many people do not wish to remain on medication for indefinite periods, or cannot tolerate its side effects."

Mindfulness-based cognitive therapy (MBCT) works by teaching people who have experienced depression the skills to identify thoughts and feelings linked with depression when they encounter them. By responding constructively to these depressive thoughts, a full relapse may be avoided.

The UK-based researchers recruited 424 adults for their study who had recurrent major depression and were taking antidepressants. The participants were randomly assigned to either stay on their medication or to slowly come off their antidepressants and receive MBCT.

The 212 participants in the MBCT group attended eight group sessions that lasted for 2.5 hours each, which also involved daily homework exercises. These participants were also given the option of attending four follow-up sessions over a year-long period.

Similar outcomes reported for both groups over 2-year follow-up

The Structured Clinical Interview for DSM-IV psychiatric diagnostic interview tool was used to assess all trial participants at regular intervals over a follow-up period of 2 years.

The researchers found that 44% of the MBCT group participants and 47% of the participants on antidepressant medication relapsed over the 2-year follow-up period.

Five adverse events - including two deaths - were reported across both groups but were not considered to be related to either the interventions or the study.

Prof. Kyuken says of the study's results:

"Whilst this study doesn't show that mindfulness-based cognitive therapy works any better than maintenance antidepressant medication in reducing the rate of relapse in depression, we believe these results suggest a new choice for the millions of people with recurrent depression on repeat prescriptions."

The authors report that theirs is the largest trial of any mindfulness-based approach to date, and that the study's validity was demonstrated through high rates of treatment adherence among both intervention groups and a relatively long follow-up.

One limitation of the study was that the recruitment strategy consisted of inviting patients who were already taking maintenance antidepressants rather than recruiting patients who were discussing their options for preventing relapse with their doctor.

In a linked comment, Prof. Roger Mulder, from the University of Otago in New Zealand, writes that as MBCT is a group treatment it may also reduce treatment costs and the number of trained staff needed:

"We therefore have a promising new treatment that is reasonably cost effective and applicable to the large group of patients with recurrent depression."

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Are people who bite their nails perfectionists?

Pulling hair, biting nails, picking skin - these are common, if frustrating, behaviors. But what do they mean for the people who suffer from these repetitive behaviors? Researchers from the Institut universitaire en santé mentale de Montréal and the University of Montreal, Canada, investigate in a new study.

The researchers found that participants engaged in repetitive behaviors when under stress or when they felt bored or frustrated, but not when they were relaxed.

"Chronic hair-pulling, skin-picking disorder and nail-biting and various other habits are known as body-focused repetitive behaviors. Although these behaviors can induce important distress, they also seem to satisfy an urge and deliver some form of reward,'' says principal investigator Kieron O'Connor.

O'Connor and colleagues studied 24 individuals with these repetitive behaviors and compared them with 24 control subjects who did not have body-focused repetitive behaviors.

The participants completed questionnaires to assess emotions such as boredom, anger, guilt, irritability and anxiety, and also took part in a clinical evaluation conducted over the phone.

Next, the participants were exposed to different experimental situations, each designed to stir one of four emotions:

• Stress
• Relaxation
• Frustration
• Boredom.

In some cases, these experimental situations involved the participants viewing videos - such as of a plane crash (stress) or waves on a beach (relaxation). To prompt frustration in the participants, the researchers set their subjects a task that was described as "easy and quick," but which in reality was difficult and long. To provoke boredom, they simply left the participant in a room on their own for 6 minutes.

The team found that, during the boredom and frustration experiments, subjects with a history of body-focused repetitive behaviors reported a stronger desire to engage in the behaviors. However, participants were not more likely to pull their hair, bite their nails or pick their skin during the relaxation experiment.

According to the authors of the study - which is published in the Journal of Behavior Therapy and Experimental Psychiatry - these results confirm that participants engage in these behaviors when under stress or when they feel bored or frustrated, and as such are not simply "nervous" habits.

Repetitive behaviors may be 'perfectionistic'

O'Connor explains the study's findings:

"We believe that individuals with these repetitive behaviors may be perfectionistic, meaning that they are unable to relax and to perform tasks at a 'normal' pace. They are therefore prone to frustration, impatience and dissatisfaction when they do not reach their goals. They also experience greater levels of boredom."

"The findings suggest that individuals suffering from body-focused repetitive behaviors could benefit from treatments designed to reduce frustration and boredom and to modify perfectionist beliefs," concludes first author Sarah Roberts.

A 2006 study by scientists at Duke University Medical Center in Durham, NC, suggested that gene mutations may cause compulsive pulling of the hair, also known as trichotillomania.

Trichotillomania affects 3-5% of the general population and often results in noticeable patches of baldness, though people with this impulse control disorder - which may be accompanied by anxiety, depression, obsessive compulsive disorder or Tourette syndrome - often do not seek treatment.

The Duke researchers identified an association between two mutations in the gene SLITKR1 and trichotillomania, although the scientists said the mutations only account for a small percentage of trichotillomania cases.

However, as impulse control disorders are typically blamed on a person's upbringing or life experiences, these findings were considered significant as they offered a biological basis for these conditions.

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Loneliness and social isolation linked to early mortality

There are a number of health and lifestyle factors - obesity, smoking, air pollution - that are known to be risk factors for early mortality and receive considerable attention. New research has suggested that social connections should be added to this list, with a study finding loneliness and social isolation to be risk factors for all ages.

The researchers suggest that the more positive psychology that individuals have, the better they can function, both emotionally and physically.

Psychologists from Brigham Young University in Provo, UT, discovered in a meta-analysis that loneliness and social isolation better predicted premature death among populations aged less than 65 years, despite older people being more likely to be lonely and having a higher mortality risk overall.

"The effect of this is comparable to obesity, something that public health takes very seriously," says lead author Julianne Holt-Lunstad. "We need to start taking our social relationships more seriously."

Previous research has demonstrated that social connections can have a positive influence on physical well-being as well as psychological and emotional well-being. Until now, no meta-analysis had been conducted where the effect of social isolation and loneliness on mortality has been the focus.

Although the two terms sound similar, loneliness and social isolation can be very different in appearance. An individual who is surrounded by lots of other people can still feel lonely while some people prefer to be alone and foster isolation from others.

Despite these differences, however, the study found that the effects on premature mortality were the same for both loneliness and social isolation.

Researchers predict a 'loneliness epidemic' in the future

For the study, the researchers analyzed data from 70 studies conducted between 1980 and 2014, featuring a total of over 3 million participants. The data included information regarding loneliness, social isolation and living alone.

After controlling for variables such as age, gender, socioeconomic status and pre-existing health conditions, the researchers found that social isolation was linked to an increased risk of premature mortality. Conversely, the presence of social relationships was found to have a positive influence on health.

The study did, however, utilize data from a narrow range of ages, with the majority of the data coming from older adults. The authors acknowledge that less than a quarter of the studies analyzed involved people with an average age of 59 or younger, and only 9% of studies involved participants younger than 50 at intake.

The researchers state that the effects on physical health caused by loneliness and social isolation are comparable to those caused by obesity, with current evidence indicating "that heightened risk for mortality from a lack of social relationships is greater than that from obesity." They write:

"The current status of research on the risks of loneliness and social isolation is similar to that of research on obesity 3 decades ago - although further research on causal pathways is needed, researchers now know both the level of risk and the social trends suggestive of even greater risk in the future."

Due to advances in technology and the evolution of the Internet, it may seem as though people are closer together than ever before. However, the number of people feeling lonely appears to be on the rise.

"Not only are we at the highest recorded rate of living alone across the entire century, but we're at the highest recorded rates ever on the planet," says co-author Tim Smith. "With loneliness on the rise, we are predicting a possible loneliness epidemic in the future."

Despite the limitations of the study, the authors believe that their findings justify raising a warning about increasing rates of social isolation.

Last year, Medical News Today reported on a study that found extreme loneliness can increase an older person's risk of premature death by 14%.

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Memories of error 'improve our learning speed'

Researchers at Johns Hopkins Medicine in Baltimore, MD, think they have discovered why people learn an identical task faster on subsequent attempts. Publishing their findings in Science Express, the team says our memories of error are the key to faster learning.

The scientific name for the small differences between our expectations of an action and the reality of that action is "prediction errors."

The researchers note that when people perform a task - such as opening a door - their brains make comparisons of how the door moved with how they expected the door to move. This information is calculated in a way that allows the person to perform the task more efficiently next time.

The scientific name for the small differences between our expectations of an action and the reality of that action is "prediction errors." We learn prediction errors in a largely unconscious way.

To further investigate how the brain learns prediction errors, the researchers devised an experiment involving a joystick and a pair of dots on a screen.

The participants were told to guide a blue dot toward a red dot on the screen using the joystick. However, the participants were unable to see the joystick that they were holding, and the blue dot could also be programmed by the researchers to move in an off-kilter way.

To overcome the off-kilter movement of the dot, the participants were required to compensate their joystick movements accordingly. Typically, after a few attempts, they would adjust their movements to guide the blue dot to its target.

The researchers observed that the participants responded more quickly to small errors that pushed them consistently in one direction than to larger errors that were less consistent.

David Herzfeld, a graduate student in Shadmehr's laboratory who led the study, explains: "They learned to give the frequent errors more weight as learning cues, while discounting those that seemed like flukes."

Reza Shadmehr, PhD, a professor in the Department of Biomedical Engineering at Johns Hopkins, compares the experiment to his proficiency as a tennis player.

"I'm much better in my second 5 minutes of playing tennis than in my first 5 minutes," he says, "and I always assumed that was because my muscles had warmed up. But now I wonder if warming up is really a chance for our brains to re-experience error."

'Two processes happening simultaneously'

Further explaining the experience of learning a new motor task, Dr. Shadmehr says there appear to be two processes happening simultaneously. One of these is the learning of motor commands, and the other is critiquing the learning, "much the way a 'coach' behaves."

"Learning the next similar task goes faster, because the coach knows which errors are most worthy of attention. In effect, this second process leaves a memory of the errors that were experienced during the training, so the re-experience of those errors makes the learning go faster."

Daofen Chen, PhD, a program director at the National Institute of Neurological Disorders and Stroke, who co-funded the study, says that the research is a significant step toward understanding how we learn motor skills:

"The results may improve movement rehabilitation strategies for the many who have suffered strokes and other neuromotor injuries."

In the next component of the research, the team will examine which brain region is responsible for the "coaching" role in assigning different weights to various types of error.

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Will losing weight really make you happier?

Although physical health is significantly improved by weight loss, the effects of losing weight on mental health are less clear, according to a new study by University College London researchers in the UK.

"People should not expect weight loss to instantly improve all aspects of life," say the researchers.

The study, which is published in the journal PLOS ONE, looked at 1,979 overweight and obese people in the UK.

It found that people who lost 5% or more of their original weight over 4 years showed significantly improved physical health. However, these people were more likely to report low mood than participants who stayed within their initial weight.

In the study, 14% of the participants lost at least 5% of their body weight - the mean weight loss was 6.8 kg per person.

Adjusting their results to take into account serious health issues and major life events that might cause weight loss and depressed mood, the researchers calculated that the participants who lost weight were 52% more likely to report symptoms of depression.

Lead author Dr. Sarah Jackson, of University College London's Epidemiology and Public Health department, says:

"We do not want to discourage anyone from trying to lose weight, which has tremendous physical benefits, but people should not expect weight loss to instantly improve all aspects of life."

She adds that "aspirational advertising by diet brands" may set unrealistic expectations about weight loss by offering what appear to be instant life improvements. Dr. Jackson advises that people should be realistic about weight loss and be prepared for the challenges:

"Resisting the ever-present temptations of unhealthy food in modern society takes a mental toll, as it requires considerable willpower and may involve missing out on some enjoyable activities. Anyone who has ever been on a diet would understand how this could affect well-being.

However, mood may improve once target weight is reached, and the focus is on weight maintenance. Our data only covered a 4-year period so it would be interesting to see how mood changes once people settle into their lower weight."

She also says that health care professionals should monitor both the physical and mental health of patients when recommending weight loss and offer ongoing support as needed.

What were the study's limitations?

Although the researchers attempted to factor in major life events that could confound results, such as bereavement, which is known to be associated with both weight loss and depression, they acknowledge that data on this was limited.

The bereavement data only covered parents and spouses during the study, and did not take into account deaths of children, close friends or non-marital partners, or the deaths of parents or spouses shortly before the study commenced.

Another major life event that the study did not have data for that could have caused weight loss and depression was job loss.

The study participants were predominantly white, older adults. It is possible, therefore, that the effects of weight loss might be different among different ethnic groups or younger adults.

Also, the researchers admit problems with the measure of well-being used in the study, explaining:

"The use of an arbitrary, unvalidated threshold to indicate low levels of well-being is also problematic, and we observed some differences in results when well-being data were analyzed continuously, so these results should be interpreted with caution."

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Antidepressants linked to higher risk of type 2 diabetes

A new systematic review of published studies suggests when prescribing antidepressant medication, clinicians should be extra aware that they are linked to raised risk for type 2 diabetes, although the study does not suggest the drugs are the direct cause.
Reporting their findings in the latest issue of Diabetes Care, researchers from the University of Southampton say use of antidepressants has risen sharply over recent years, and there are concerns they may have an adverse effect on glucose metabolism.
They note 46.7 million prescriptions for antidepressants were issued in 2011 in the UK.
Antidepressant use has also soared in the US, where a 2011 study found they are now the third most widely prescribed group of drugs.
Several studies have shown that antidepressant use is linked to diabetes, but the results have been varied, depending on the methods and numbers involved and also on the types of drugs themselves.
For instance, one study that found a link between antidepressants and risk for type 2 diabetes discovered the risk almost doubled in patients using two types of drugs at the same time: tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs).

Antidepressant users more likely to have type 2 diabetes

Researchers found a link between people who take antidepressants and type 2 diabetes, although it does not mean there is a direct causal effect.

For their systematic review, Southampton health psychologist Dr. Katharine Barnard and colleagues assessed 22 studies and three previous reviews that looked at the link between antidepressant use and risk for type 2 diabetes.
They found that overall, people on antidepressants were more likely to have type 2 diabetes.
Within that, however, the picture is somewhat "confused, with some antidepressants linked to worsening glucose control, particularly with higher doses and longer duration, others linked with improved control, and yet more with mixed results."
They note that although study quality was variable, the more recent, larger studies suggest a modest effect.
The researchers also propose that different types of antidepressants may be linked to different amounts of risk and call for long-term randomized, controlled trials to examine the effects of individual drugs.

Several 'plausible' explanations

While their review was not designed to investigate causes, the team says there could be several plausible explanations for the link. For instance, some antidepressants cause patients to put on weight, which in itself increases risk for type 2 diabetes.
But they also point out that some of the studies they reviewed found the raised risk for type 2 diabetes persisted when they took out the effect of weight gain, suggesting other factors could be involved.
Dr. Barnard says:

"Our research shows that when you take away all the classic risk factors of type 2 diabetes; weight gain, lifestyle etc, there is something about antidepressants that appears to be an independent risk factor."

She says that in light of rising prescriptions, "this potential increased risk is worrying," and:
"Heightened alertness to the possibility of diabetes in people taking antidepressants is necessary until further research is conducted."
Co-author Richard Holt, professor in Diabetes and Endocrinology at Southampton, adds:

"While depression is an important clinical problem and antidepressants are effective treatments for this debilitating condition, clinicians need to be aware of the potential risk of diabetes, particularly when using antidepressants in higher doses or for longer duration."

He says doctors prescribing antidepressants should be aware of this raised risk for diabetes and ensure they monitor patients for the condition, as well as take steps to reduce the risk by encouraging changes to lifestyle.

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Suicide Can Be Contagious Among Teens

Suicide can be contagious, especially among teenagers, according to a new study published in the Canadian Medical Association Journal (CMAJ).

The research suggests that one person's suicide can influence another person's suicidal thoughts or behavior, and this is particularly seen among younger adolescents.

Additionally, the teens do not have to be personally associated with the suicide victim to start thinking about suicide or to attempt suicide themselves, the investigators discovered.

Dr. Ian Colman, an assistant professor at the Department of Epidemiology and Community Medicine and Canada Research Chair in Mental Health Epidemiology, said:

"When someone dies, particularly a young person, the deceased is described by their loved ones in the media and in social media in glowing, romantic terms, often mentioning how beautiful the child was.

Talk like this is common when any child dies, but it can be dangerous when talking about suicide. When other vulnerable youth are reading or hearing about this, they see the reports about how wonderful the person was and they want their loved ones to feel the same way about them."

A previous study suggested that teens are at the highest risk of attempting suicide within two years after a parent has attempted suicide or has received inpatient care because of a mental disorder.

For the current investigation, the experts gathered and analyzed data from more than 22,000 volunteers between the ages of 12 and 17.

According to the results, 12-to-13 year olds who had been exposed to suicide had a five times higher risk of contemplating suicide themselves or to say that they had attempted suicide.

After factoring in the adolescent's personal knowledge of the person who died, the scientists were surprised to see that there was nearly no difference in these statistics.

As the teenager grows older, the influence seems to decline, the researchers explained. Fourteen-to-fifteen year olds who were exposed to suicide were three times as likely to think about or attempt suicide, while those aged 16-to-17 were twice as likely.

These results have practical implications for experts in the mental health field concerned with prevention.

Dr. Colman said:

"It's clear that these results support the suicide contagion hypothesis, especially among younger adolescents.  It most certainly supports school-based interventions as opposed to high-risk interventions aimed solely at the friends of the deceased."

The report emphasizes the unfortunate consequences that may unintentionally result when the public pays too much attention to individual suicide cases.

It is critical to re-evaluate current strategies that are associated with the support and creation of mental health programs, the authors said.

A study from earlier this year indicated that most suicidal teens being treated still attempt suicide, suggesting that they are not being given the proper treatment.

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Father's Mental Health Linked To Child's Behavior

An expectant father's psychological distress may be linked to his toddler's emotional and behavioral development.

The finding came from new research published in the journal Pediatrics which analyzed over 31,000 Norwegian kids and their parents.

Several previous studies have shown that the mental health of a mother, during and after her pregnancy, may have an effect on the health of the child. One study showed that children's early experiences with a mother suffering from a severe mental illness can influence their long-term health and development.

Anne Lise Kvalevaag, leading researcher and a doctoral candidate in psychology at the University of Bergen in Norway, said:

"The results of this study point to the fact that the father's mental health represents a risk factor for child development, whereas the traditional view has been that this risk in large is represented by the mother. The father's mental health should therefore be addressed both in research and clinical practice."

The team of experts interrogated the dads when the moms were 4 to 5 months pregnant. They were asked about their mental health, for instance, whether they felt depressed or afraid.

The mental health of the moms was provided by the mothers themselves, as well as the behavioral, social, and emotional development of their children when they were 3 years old.

Rather than looking at particular diagnoses in kids, the scientists collected information on whether they had experienced frequent mood shifts, got into fights, or had feelings of anxiety, explained Kvalevaag.

High levels of psychological distress were reported by 3% of the dads. The team discovered a link between the mental health of the father and the development of a child.

The children who had the most emotional issues at age 3 were the ones whose dads were the most distressed. The researchers pointed out that this study did not demonstrate a direct cause-and-effect association.

The authors explained that there are various possible means that may account for the relationship. For example, Kvalevaag explained, the fathers may be passing on a genetic risk to the child. The mental health of the soon-to-be mom could also be influenced by the dad's depression, therefore, causing an effect on the unborn baby, suggested another scientist.

"If a father is highly distressed, that could affect the mom's secretion of hormones during pregnancy, it could affect her sleep, her own mental status," said Daniel Armstrong, professor of pediatrics and director of the Mailman Center for Child Development at the University of Miami Miller School of Medicine.

"The prenatal mental state of the father is likely to predict the postnatal mental health of the father and this may also account for some of the associations found," Kvalevaag revealed.

The experts noted that the study had a few limitations, for example, the mental health data was taken from self-reports, which are not always reliable.

Prior studies have indicated that infants are seen as being more troublesome by depressed moms as opposed to more impartial onlookers, explained Michael Rice, associate clinical director of the Behavioral Health Education Center of Nebraska at the University of Nebraska Medical Center in Omaha.

The answer to this problem may be fairly simple, Armstrong said. "When mom comes in for appointments, we should at least be raising the question of how dad's doing. That's probably a question that's never asked."

Rice concluded:

"This study gives a more complete picture. When we talk about preventative mental health and preventing these things in the kids, we really need resources there at the prenatal stage for both the mother and the father."

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Genetic Clue Discovered For Why Women Outlive Men

A new study of mitochondrial DNA in fruit flies offers a number of clues that might explain why females tend to outlive males across much of the animal kingdom, including humans.

Researchers from Monash University in Australia and Lancaster University in the UK, write about their work in the 2 August online issue of Current Biology.

They found male fruit flies appear to have mutations in their mitochondrial DNA that affect how fast they age and how long they live.

Scientists use fruit flies as models for studies in genes and aging because their biological processes are remarkably similar to that of other animals, such as humans, and with a lifespan of about a month, it doesn't take too long to investigate generational effects.

Senior author Damian Dowling, a research fellow in the Monash School of Biological Sciences, told the press:

"All animals possess mitochondria, and the tendency for females to outlive males is common to many different species. Our results therefore suggest that the mitochondrial mutations we have uncovered will generally cause faster male aging across the animal kingdom."

"Intriguingly, these same mutations have no effects on patterns of aging in females. They only affect males," he added.

Mitochondria are special subunits of cells, about the same size as bacteria, that provide the energy for life. They combine sugar and oxygen into adenosine triphosphate or ATP, molecular packets of energy that are usable by cells.

Mitochondria have their own DNA that is quite separate from the cellular DNA in the nucleus of the cell.

And, unlike cellular DNA, which is inherited from the sperm and egg that fuse to make the new individual, mitochondrial DNA comes only from the egg.

Thus, as mitochondrial DNA is passed down from generation to generation, the process of natural selection has no opportunity to "screen out" mutations in mitochondrial DNA that might be harmful to males. The researchers refer to this as a "sex-specific selective sieve".

For their study, Dowling and colleagues looked at differences in longevity and biological aging in male and female fruit flies whose mitochondria came from different origins.

They found genetic variations in both male and female mitochondrial DNA, but only the male ones could be linked to life expectancy. There weren't just a few mutations in one place, there were several, spread all over the mitochondrial genome:

"... our results indicate that the mitochondrial mutation loads affecting male aging generally comprise numerous mutations over multiple sites," they write.

The researchers suggest the mutations are entirely due to the way mitochondrial DNA is passed down through the female line.

"If a mitochondrial mutation occurs that harms fathers, but has no effect on mothers, this mutation will slip through the gaze of natural selection, unnoticed. Over thousands of generations, many such mutations have accumulated that harm only males, while leaving females unscathed," Dowling explained.

In an earlier study that looked at the effect of mitochondria being passed down the female line, the team had also discovered a link with male infertility.

Dowling said combining this latest study with their earlier work suggests mitochondria are "hotspots" for mutations that influece male health.

"What we seek to do now is investigate the genetic mechanisms that males might arm themselves with to nullify the effects of these harmful mutations and remain healthy," said Dowling.

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How Cat Litter Parasite Toxoplasma Gondii Influences The Brain

New research led by a team at the Karolinska Institutet in Sweden reveals for the first time what the common "cat litter parasite" Toxoplasma gondii does once it gets into the brain. The study is important in the light of recent observations linking the parasite to risk-taking and other human behaviours, and associations with mental illness.

The researchers write about their findings in a paper published online on 6 December in the journal PLoS Pathogens.

Toxoplasma Infection

Infection by Toxoplasma gondii or Toxoplasma is called Toxoplasmosis. Estimates suggest between 30 and 50% of the global human population is infected. In Sweden the figure is nearer 20%. In the US, the Centers for Disease Control and Prevention (CDC), puts the number of infected men, women and children at 60 million. Animals can also become infected, especially domestic cats.

People usually contract the parasite by eating poorly cooked meat: according to the CDC, toxoplasmosis is the leading cause of death from foodborne illness in the US. Another way people become infected is by touching cat feces, hence the expression "cat litter parasite" because one way of touching cat feces is handling the cat litter tray.

The vast majority of people infected have few symptoms because their immune system usually stops the parasite from causing illness. In newly infected adults the parasite can cause mild flu-like symptoms, and then it usually enters a chronic dormant phase which was thought to be symptom free.

However, when the parasite enters the brain of fetuses, and people with weak immune systems, it can be fatal. Because of this risk, uninfected pregnant women should not touch cat litter trays.

Links to Mental Illness, Risk-Taking Behavior

There is an emerging view that the toxoplasmosis parasite is active to some extent during what was previously regarded as a purely "dormant phase".

For example, rats infected with the parasite lose their fear of cats, and are even attracted by their scent, making them easy prey. Scientists have suggested this is how the parasite assures its own survival and propagation: the cats eat the infected rats, shed more parasite through their feces, and that in turn helps to infect more rats.

Other studies have found schizophrenia, depression, anxiety, and other mental diseases are more common in people with toxoplasmosis, and there is also evidence to suggest infection by the parasite is linked to more extroverted, aggressive and risk-taking behavior.

In a study published in the July 2012 issue of the Archives of Psychiatry, researchers from Denmark's Statens Serum Institut and the University of Maryland in the US, found that women carrying IgG antibodies to Toxoplasma gondii when giving birth have a higher risk of self-harm or suicide later on.

While such a description sounds alarming, study senior author Antonio Barragan, researcher at the Center for Infectious Medicine at Karolinska Institutet and the Swedish Institute for Communicable Disease Control, says:

"At the same time, it's important to emphasize that humans have lived with this parasite for many millennia, so today's carriers of Toxoplasma need not be particularly worried."

Once in the Brain, Toxoplasma Spurs GABA Secretion

The researchers didn't examine how the toxoplasmosis parasite changes host behavior, they were more interested in what it does in the brain.

They found that it takes over one of the brain's neurotransmitters: the chemical messengers that carry signals between various parts of the brain.

In one test tube experiment, they infected human dendritic cells with the parasite. Dendritic cells form the frontline of the immune system, and play a key role in triggering and adapting immune responses. Once infected, the dendritic cells started secreting GABA, a chemical messenger.

In another experiment with live mice, the researchers tracked infected dendritic cells from their initial point of infection to other parts of the brain where they continued to affect the GABA system.

In their author summary, the researchers note:

"Dendritic cells are considered the gatekeepers of the immune system but can, paradoxically, also mediate dissemination of the parasite."

"This study establishes that GABAergic signaling modulates the migratory properties of dendritic cells and that the intracellular pathogen Toxoplasma gondii sequesters the GABAergic signaling of dendritic cells to assure propagation," they add.

GABA does a number of things, but one of them is to inhibit the sensations of fear and anxiety. People with mental illnesses such as schizophrenia, bipolar diseases, anxiety syndrome and depression show disturbances in GABA systems.

Barragan describes the parasite's ability to make the immune cells secrete GABA as "very clever" and says the finding was "as surprising as it was unexpected".

The researchers call for further studies.

"It would now be worth studying the links that exist between toxoplasmosis, the GABA systems and major public health threats," Barragan suggests.

A grant from the Swedish Research Council helped fund the study.

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