Story telling and brain chemistry

The Evolutionary Advantage of Depression By Brian Gabriel Oct 2 2012, 11:08 AM ET 38

 

Genes influencing depression also bolstered our ancestors' immune systems -- an understanding that's informing experimental therapies. 

Van Gogh, At Eternity's Gate (Wikipedia)

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More people die from suicide than from murder and war combined, throughout the world, every year. In the United States, suicide recently surpassed automobile accidents as the leading cause of violence-related death, according to a study appearing in the American Journal of Public Health.
The majority of individuals who commit suicide suffer from depression or another mood disorder. Depression is a devastating illness characterized by persistent sadness and myriad well-known symptoms. Increasingly, researchers are identifying how genes contribute to depression. As we learn more about the human genome, scientists are finding evidence that while depression seems incredibly maladaptive, it was actually adaptive (helpful) to our ancestors.
Recently Dr. Andrew Miller and Dr. Charles Raison, physicians at Emory University and the University of Arizona, respectively, authored a paper "The evolutionary significance of depression in pathogen host defense" in which they proposed that some of the alleles (forms of genes) that increase one's risk for depression also enhance immune responses to infections.
Commenting on their hypothesis, Dr. Miller noted, "Most of the genetic variations that have been linked to depression turn out to affect the function of the immune system." Dr. Charles Raison of the University of Arizona added, "The basic idea is that depression and the genes that promote it were very adaptive for helping people -- especially young children -- not die of infection in the ancestral environment."
As recently as 1900, the top 3 causes of death in the U.S. were via infectious agents: pneumonia, tuberculosis, and diarrhea. Infants and young children were especially susceptible as 30.4% of all deaths occurred before the age of 5 years.

Depressive symptoms like social withdrawal, lack of energy, and a loss of interest in once enjoyable activities were actually advantageous to our ancestors.

Thanks to improvements in public health and medicine (improvements like antibiotics), not a single one of the previous 3 leading causes of death are among the top 5 killers in the U.S today. Over the past century, infant mortality has dropped substantially, so that by 1997 only 1.4% of all deaths occurred before the age of 5 years. Although infection is no longer a top killer, infection was the primary cause of death for many of our ancestors.
Today, certain mutated versions of a gene called "NPY" are associated with increased inflammation (an immune process helpful in fighting off infections). Mutated NPY genes likely allowed our ancestors to better fight off infections (especially in childhood), and individuals with the mutated NPY gene were more likely to pass along the mutated NPY gene to offspring.
Interestingly, researchers at the University of Michigan's Molecular and Behavioral Neuroscience Institute discovered that individuals with major depressive disorder were more likely to have the mutated NPY gene. The normal NPY gene codes for higher levels of a neurotransmitter known as Neuropeptide Y, which appears to help ward off depression by increasing one's tolerance of stress. So the same mutated NPY gene that likely protected our ancestors against pathogens also increases our chance of developing depression.
Drs. Miller and Raison believe that acute (or severe but short-term) stress can not only lead to depression, but also jump-start the immune system. The physicians note that in the environments in which our ancestors lived, acute stress was often associated with the threat of physical harm or physical wounds. And unlike today, wounds readily led to infection and death. Therefore, Drs. Miller and Raison believe that evolution favored individuals whose immune systems operated under a "smoke-detector principle."
Although smoke detectors often react to false alarms (for me, burnt toast), if you removed the detector's battery and a real fire occurred, the consequences could be severe. Similarly, immune responses to acute stress are typically not necessary -- not every stressful situation results in a wound and infection. However, if our ancestors became wounded even a single time and didn't experience a piqued immune response, they might die from an infection.
It turns out that depression may not be a mere trade-off for a vigorous immune response. Dr. Miller suggests that depressive symptoms like social withdrawal, lack of energy, and a loss of interest in once enjoyable activities were actually advantageous to our ancestors. For example, a loss of energy might ensure that the body can leverage all of its energy to fight an infection. Also, social withdrawal minimizes the likelihood of being exposed to additional infectious agents. In this way, Drs. Miller and Raison note that "depressive symptoms are inextricably intertwined with -- and generated by -- physiological responses to infection that, on average, have been selected as a result of reducing infectious mortality across mammalian evolution."
Recently Dr. Miller and Dr. Raison completed a separate study in which they attempted to treat patients with "difficult to treat" depression with a novel drug infliximab. Infliximab works by disrupting communication between immune cells and consequently reduce inflammation.
While infliximab did not significantly improve depression symptoms in the group being studied as a whole, it did reduce depression symptoms among a subset of study participants who showed elevated levels of inflammation. Inflammation was measured using blood tests for "C-reactive protein" (CRP). The higher the participants' level of CRP, the more likely the participant was to respond positively to infliximab.
As Drs. Miller and Raison suggest, the theory that depression evolved to better resist infectious agents could lead to improvements within the field of immunology and novel treatments for depression. The physicians also suggest that in the future, we may be able to utilize simple biomarkers (like CRP) to predict which individuals will best respond depression treatments that modulate our immune systems (like infliximab).
Drs. Miller and Raison concede that chronic stress has been shown to impair the immune system. However, evolutionary processes may still allow for improved infection responses to acute (or short-term) stressors.


The physicians also noted that inflammatory biomarkers are not elevated in all individuals with depression. Individuals with major depressive disorder and elevated levels of inflammation may represent a unique subset of individuals with depression. Therefore, while immune-modulating therapies may be effective in treating some cases of depression, these therapies may not be effective against all types of depression.

Learned Optimism: Martin Seligman on Happiness, Depression, and the Meaningful Life by Maria Popova

“The illiterate of the 21st century,” Alvin Toffler famously said, “will not be those who cannot read and write, but those who cannot learn, unlearn, and relearn.” Our outlook on the world and our daily choices of disposition and behavior are in many ways learned patterns to which Toffler’s insight applies with all the greater urgency — the capacity to “learn, unlearn, and relearn” emotional behaviors and psychological patterns is, indeed, a form of existential literacy.
Last week, Oliver Burkeman’s provocatively titled new book, The Antidote: Happiness for People Who Can’t Stand Positive Thinking, prompted me to revisit an old favorite by Dr. Martin Seligman, father of the Positive Psychology movement, who was once elected President of the American Psychological Association by the largest vote in the organization’s history and under whom I studied in my college days. Learned Optimism: How to Change Your Mind and Your Life (public library), one of these 7 must-read books on optimism, was originally published 20 years ago and remains an indispensable tool for learning the cognitive skills that decades of research have shown to be essential to well-being — an unlearning those that hold us back from authentic happiness.
Seligman begins by identifying the three types of happiness of which our favorite psychology grab-bag term is composed:

‘Happiness’ is a scientifically unwieldy notion, but there are three different forms of it if you can pursue. For the ‘Pleasant Life,’ you aim to have as much positive emotion as possible and learn the skills to amplify positive emotion. For the ‘Engaged Life,’ you identify your highest strengths and talents and recraft your life to use them as much as you can in work, love, friendship, parenting, and leisure. For the ‘Meaningful Life,’ you use your highest strengths and talents to belong to and serve something you believe is larger than the self.

He then defines optimism and pessimism, pointing out the challenge to self-identify as either, and offers a heartening, heavily researched reassurance:

The optimists and the pessimists: I have been studying them for the past twenty-five years. The defining characteristic of pessimists is that they tend to believe bad events will last a long time, will undermine everything they do, and are their own fault. The optimists, who are confronted with the same hard knocks of this world, think about misfortune in the opposite way. They tend to believe defeat is just a temporary setback, that its causes are confined to this one case. The optimists believe defeat is not their fault: Circumstances, bad luck, or other people brought it about. Such people are unfazed by defeat. Confronted by a bad situation, they perceive it as a challenge and try harder.
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I have seen that, in tests of hundreds of thousands of people, a surprisingly large number will be found to be deep-dyed pessimists and another large portion will have serious, debilitating tendencies towards pessimism. I have learned that it is not always easy to know if you are a pessimist, and that far more people than realize it are living in this shadow.
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A pessimistic attitude may seem so deeply rooted as to be permanent. I have found, however, that pessimism is escapable. Pessimists can in fact learn to be optimists, and not through mindless devices like whistling a happy tune or mouthing platitudes…but by learning a new set of cognitive skills. Far from being the creations of boosters or of the popular media, these skills were discovered in the laboratories and clinics of leading psychologists and psychiatrists and then rigorously validated.

Seligman, however, also corroborates what’s perhaps Burkeman’s most central admonition — that the extreme individualism and ambition our society worships has created a culture in which the fear of failure dictates all. As Seligman puts it:

Depression is a disorder of the ‘I,’ failing in your own eyes relative to your goals. In a society in which individualism is becoming rampant, people more and more believe that they are the center of the world. Such a belief system makes individual failure almost inconsolable.
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Teaching children learned optimism before puberty, but late enough in childhood so that they are metacognitive (capable of thinking about thinking), is a fruitful strategy. When the immunized children use these skills to cope with the first rejections of puberty, they get better and better at using these skills. Our analysis shows that the change from pessimism to optimism is at least partly responsible for the prevention of depressive symptoms.

Ultimately, Seligman points to optimism not only as a means to individual well-being, but also as a powerful aid in finding your purpose and contributing to the world:

Optimism is invaluable for the meaningful life. With a firm belief in a positive future you can throw yourself into the service of that which is larger than you are.

One-Fifth of Spine Surgery Patients Develop PTSD Symptoms

ScienceDaily (Sep. 27, 2012) — Nearly 20 percent of people who underwent low back fusion surgery developed post-traumatic stress disorder symptoms associated with that surgery, according to a recent Oregon Health & Science University study published in the journal Spine.

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Past studies have noted PTSD symptoms in some trauma, cancer and organ transplant patients. But this is the first study, its authors believe, to monitor for PTSD symptoms in patients undergoing an elective medical procedure.
"It is maybe not surprising that significant surgical interventions have psychological as well as physical impacts," said Robert Hart, M.D., an orthopedic surgeon, professor of orthopedics and rehabilitation at OHSU and senior author of the study. "I think it means that we in the medical community need to monitor for these effects in our patients and to manage them when they occur."
The study found that the strongest factor in determining whether a spine surgery patient suffered PTSD symptoms after the surgery was whether the patient had a psychiatric disturbance -- depression or anxiety disorders, for example -- before the surgery. But some patients who had no such pre-surgery diagnoses also suffered PTSD symptoms after the spine surgery, the study found.
The OHSU study involved 73 of Hart's surgical patients who underwent lumbar spinal fusion surgery, a procedure in which two or more lumbar vertebrae in the back are fused together, usually including implantation of metal screws and rods as part of the procedure.
Surgeons at the OHSU Spine Center always look for other ways to deal with back pain before surgery. But sometimes, surgery is the only option. And spinal fusion is often major surgery that may involve complications and often involves a long recuperation period. The majority of patients in the study reported a good experience and had substantial relief of their pre-operative pain.
Hart said the study results might offer guidance to doctors and surgeons in advising potential spine surgery patients about the surgery. For patients at higher risk, the results suggest doctors and surgeons might offer treatment for them prior to surgery, Hart said.
"At the end of the day, I hope this will make changes in the way we prepare people for surgery, to reduce these psychological impacts. This is analogous to how we currently optimize patients' physical condition before major surgery," Hart said.
Hart said he wants to study that issue next -- and measure which pre-surgery interventions might work best to reduce or eliminate any PTSD effects.

One-Fifth of Spine Surgery Patients Develop PTSD SymptomsScienceDaily (Sep. 27, 2012) — Nearly 20 percent of people who underwent low back fusion surgery developed post-traumatic stress disorder symptoms associated with that surgery, according to a recent Oregon Health & Science University study published in the journal Spine. Share This: 50 See Also: Health & Medicine Today's Healthcare Wounds and Healing Cosmetic Surgery Mind & Brain PTSD Psychiatry Mental Health Reference Scoliosis Hysterectomy Urology Minimally invasive procedure Past studies have noted PTSD symptoms in some trauma, cancer and organ transplant patients. But this is the first study, its authors believe, to monitor for PTSD symptoms in patients undergoing an elective medical procedure. "It is maybe not surprising that significant surgical interventions have psychological as well as physical impacts," said Robert Hart, M.D., an orthopedic surgeon, professor of orthopedics and rehabilitation at OHSU and senior author of the study. "I think it means that we in the medical community need to monitor for these effects in our patients and to manage them when they occur." The study found that the strongest factor in determining whether a spine surgery patient suffered PTSD symptoms after the surgery was whether the patient had a psychiatric disturbance -- depression or anxiety disorders, for example -- before the surgery. But some patients who had no such pre-surgery diagnoses also suffered PTSD symptoms after the spine surgery, the study found. The OHSU study involved 73 of Hart's surgical patients who underwent lumbar spinal fusion surgery, a procedure in which two or more lumbar

Diet Sodas: Changing Your Brain And Your Waistline - from Lumosity.com

Diet sodas may not be helping you lose weight—in fact, these and other artificially sweetened foods may sabotage your diet by confusing and rewiring your brain’s reward centers. This study from the journal Physiology & Behavior is yet another example of how lifestyle choices can alter your brain—negatively or positively.

Scanning diet soda drinkers' brains

The University of San Diego study followed 24 young adults: half the group drank at least one serving of diet soda every day, while the other half avoided the artificially sweetened drinks. These adults were then hooked up to brain scanning equipment while scientists fed them water alternately flavored by natural and artificial sweeteners—then the researchers sat back and watched what unfolded in the brain.
The results, according to University of California San Diego researchers Green and Murphy, were pronounced: “[Diet soda drinkers] who consumed a greater number of diet sodas had reduced caudate head activation. These findings may provide some insight into the link between diet soda consumption and obesity.”

Artificial sweeteners confuse reward

A little bit of background: the caudate head is a part of the brain involved in signaling reward and controlling food intake—and its decreased activity in the brains of diet soda drinkers has substantial implications.
Researchers posit that consumption of diet soda had confused the reward loops normally processed by the caudate head: because sweetness was no longer a reliable indicator of incoming calories, the brain had trained itself to respond less in the face of sweet flavors. Unreliable sweet tastes threw off normal predictions about calories and energy in the changed brains of diet soda drinkers—making it more likely that these people would consume additional calories later in the day.

Small choices can affect your brain

This newest study is pretty preliminary; it’s difficult to say how drastically diet sodas can affect bigger questions of lifestyle and health based on such short-term brain activation patterns. Still, this recent investigation provides an interesting reflection on how choices and actions made in everyday life can powerfully influence the way your brain is wired—in other words, the concept of neuroplasticity.
We can’t always foresee the unintended negative responses our brain makes—who would have thought diet coke might do quite the opposite of what its name suggests?—but there are positive ways to harness your brain’s ability to change. Just a little Lumosity training every day, for example, can change your brain for the better: instead of confused reward signals, you could experience faster processing speed, quicker flexibility, and improved problem solving.

South Carolina: Military to Study Benefits of Fish Oil By THE ASSOCIATED PRESS Published: October 9, 2012

A $10 million study over three years will investigate whether a dietary supplement could help curb the number of suicides among military personnel and veterans, researchers said on Monday. The study, which is scheduled to begin in South Carolina in January, is part of the Defense Department’s focus on suicide prevention. The first part of the trial will examine the effects of daily supplements of omega-3 fatty acids on about 320 at-risk military personnel and veterans. Omega-3 fatty acids, found in fish oil, are instrumental in the repair and regeneration of brain cells.