Archive for August 11th, 2012
It’s a common prejudice that a naturalistic worldview, one based on the ideas of science, empiricism, and the clear-eyed observation of the doings of our species, ruins life’s mysteriousness.
Nothing could be further from the truth. But this common prejudice in favor of a mysticism based on fear and wishful thinking continues to prevail. This chronic mysticism has not been taken to task often enough or loudly enough by previous psychologies.
The following is a typical expression of how a naturalistic worldview supposedly robs life of mystery. Sam Keen, writing about the contributions to philosophy of the theologian Gabriel Marcel, explained in Gabriel Marcel: Makers of Contemporary Theology:
“For Marcel, the results of a naturalistic way of thinking are disastrous for human dignity. As the capacity to love, to admire, and to hope dries up, the functional man loses the ability, and even the desire, to transcend his situation of alienation and captivity.
High levels of estrogen may help protect a woman from mood disorders, while low levels of the hormone can make a woman more susceptible to trauma at certain times in her menstrual cycle, according to new research by Harvard and Emory University neuroscientists.
Depression and anxiety disorders are twice as common in women as in men, but the reason for this gender difference has remained unclear. The new research, however, suggests that women are most at risk for symptoms of post-traumatic stress disorder (PTSD) when their estrogen is low during the menstrual cycle.
“PTSD is a disorder of recovery,” said author Mohammed Milad, associate professor of psychiatry at Harvard Medical School (HMS) and director of the Behavioral Neuroscience Laboratory at Massachusetts General Hospital (MGH).
Men may be less susceptible to mood disorders since testosterone is regularly converted into estrogen in the male brain, resulting in a more steady flow of estrogen.
In healthy women and female rats, estrogen calms the fear response, according to the Harvard researchers, who were led by Kelimer Lebron-Milad, an HMS instructor of psychiatry.
The Emory researchers, led by postdoctoral researcher Ebony Glover, proved that the same is true for women suffering from PTSD. The higher their blood levels of estrogen were when they completed a fear-extinction task, the less likely women were to act startled.
Both studies used “fear-conditioning” experiments, in which the participant is trained to fear a safe “conditioned stimulus” such as a colored shape, paired with a frightening or painful “unconditioned stimulus” like a shock to the finger or a puff of air to the neck or eye.
Overall, women or female rats showed less fear to the neutral stimulus when their estrogen levels were high rather than low.
PTSD is common in women after a trauma such as rape or sexual assault, which studies say are experienced by 25 to 30 percent of women in their lifetimes, and the symptoms last on average four times as long in women as in men after trauma.
This new research suggests the reason for this vulnerability may be the monthly menstrual change in estrogen.
“People are afraid to look into the influence of sex hormones on ‘fear learning’ and extinction,” said Mohammed Milad, “because it’s such a complex system.”
When Milad studied fear as a Ph.D. student, his lab used only male rats. But when he began to study fear in humans as a postdoctoral researcher, he saw that female data were much more variable.
“The data led me there,” to sex differences, Milad said. “Since females add variance, scientists have tended to avoid studying them” in rodent research, he said. Studies of the human brain would tend to combine men and women, assuming that neurological gender differences were minimal. But this attitude is changing.
In addition, since birth control pills affect estrogen levels, they may be used as a future treatment against post-traumatic stress.
The research is published in Biological Psychiatry.
Source: Biological Psychiatry
Current and former soldiers who seek treatment for post-traumatic stress disorder (PTSD) should be screened closely for major depression since the disorder is the single strongest driver of suicidal thinking, say authors of a new Canadian study.
Researchers evaluated 250 active duty Canadian Forces, RCMP members and veterans. The study comes at a time when record numbers of suicides are being reported among American troops returning from Afghanistan and Iraq, and the number of suicides reported among Canadian forces last year reached its highest point since 1995.
In veterans suffering from post-traumatic stress disorder, about half also have symptoms of major depressive disorder during their lifetime, said the researchers.
But “the task of predicting which people may be at an increased risk of completing suicide is a complex and challenging care issue,” they said.
The study included 193 Canadian Forces vets, 55 active troops and two RCMP members referred to the Parkwood Hospital Operational Stress Injury Clinic in London, Ontario.
Soldiers and vets were screened for PTSD, major depression, anxiety disorders and alcohol abuse. The depression questionnaire also included questions about suicidal thinking.
Study participants served an average of 15 years and had been deployed an average of three times. About one-fourth had been deployed to Afghanistan at least once. Ninety-two per cent were men.
Most met the criteria for “probable” PTSD, and almost three-fourths screened positive for probable major depression.
Overall, about one-fourth — 23 percent — said that they had experienced thoughts of self-harm, or that they would be better off dead, for several days over the prior two weeks.
Another 17 percent said they had those thoughts more than half of the days in the past two weeks; six percent reported feeling this way almost every day for the previous two weeks.
As found in other studies, the researchers showed that PTSD is linked to suicidal thoughts. But “what became the biggest predictor was, specifically, depression severity,” said Dr. Don Richardson, a consultant psychiatrist at the Operational Stress Injury Clinic and an adjunct professor in the department of psychiatry at Western University in London.
“It really stresses the importance that when you’re assessing someone for PTSD it’s also critical that you assess specifically for major depression,” Richardson said. “From our limited study, it was depression severity that was the most significant predictor of having suicidal ideation.”
The concern is that soldiers seeking treatment for military-related trauma might not receive aggressive therapy for depression. Instead, the focus might be more focused on PTSD and exposure therapy.
“There’s potentially a lot of people out there who are suffering who might not be aware that there are effective treatments, and that there are clinics available across Canada that specialize in military trauma,” said Richardson.
New research has demonstrated that the effects on white matter brain volume from long-term alcohol abuse are different for men and women.
Researchers from Boston University School of Medicine (BUSM) and Veterans Affairs (VA) Boston Healthcare System also suggest that when they stop drinking, women recover their white matter brain volume more quickly than men.
Previous research has linked alcoholism with white matter reduction, according to the researchers, who explain that white matter forms the connections between neurons, allowing communication between different areas of the brain.
In this latest study, a research team, led by Susan Mosher Ruiz, Ph.D., a postdoctoral research scientist in the Laboratory for Neuropsychology at BUSM and research scientist at the VA Boston Healthcare System, and Marlene Oscar Berman, Ph.D., professor of psychiatry, neurology and anatomy and neurobiology at BUSM and research career scientist at the VA Boston Healthcare System, employed structural magnetic resonance imaging (MRI) to determine the effects of drinking history and gender on white matter volume.
They examined brain images from 42 abstinent alcoholic men and women who drank heavily for more than five years and 42 nonalcoholic men and women. The researchers found that a greater number of years of alcohol abuse was associated with smaller white matter volumes in the alcoholic men and women. In the men, the decrease was observed in the corpus callosum, while in women this effect was observed in cortical white matter regions.
“We believe that many of the cognitive and emotional deficits observed in people with chronic alcoholism, including memory problems and flat affect, are related to disconnections that result from a loss of white matter,” said Mosher Ruiz.
The researchers also found that the number of daily drinks had a strong impact on alcoholic women, with the volume loss 1.5 to 2 percent for each additional drink. Additionally, there was an 8 to 10 percent increase in the size of the brain ventricles, which are areas filled with cerebrospinal fluid (CSF) that play a protective role in the brain. When white matter dies, CSF produced in the ventricles fills the ventricular space.
The researchers also found that in men, white matter brain volume in the corpus callosum recovered at a rate of 1 percent per year for each year of abstinence. For people who abstained less than a year, the researchers found evidence of increased white matter volume and decreased ventricular volume in women, but not in men. However, for people in recovery for more than a year, those signs of recovery disappeared in women and became apparent in men.
“These findings preliminarily suggest that restoration and recovery of the brain’s white matter among alcoholics occurs later in abstinence for men than for women,” said Mosher Ruiz. “We hope that additional research in this area can help lead to improved treatment methods that include educating both alcoholic men and women about the harmful effects of excessive drinking and the potential for recovery with sustained abstinence.”
The research was published online in Alcoholism: Clinical and Experimental Research.
Source: Boston University Medical Center