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Depression Re-examined: A New Way to Look at an Old Puzzle

Depression affects approximately 10% of Americans. It can be fatal; I found estimates of suicide rates ranging from 2-15% of patients with major depression. When it doesn’t kill, it impairs functioning and can make life almost unbearably miserable. It is a frustrating condition because there is no lab test to diagnose it, no good explanation of its cause, and the treatments are far from ideal.

Jonathan Rottenberg is a psychologist and research scientist who began to study depression after his own recovery from a major depressive illness. He teaches psychology at the University of South Florida, where he is the director of the Mood and Emotion laboratory. He has launched the Come Out of the Dark campaign to start a better, richer national conversation about depression. In a new book The Depths: The Evolutionary Origins of the Depression Epidemic, he reviews insights from recent experiments and asks a number of difficult questions, such as why humans evolved to be subject to incapacitating depressions. He comes up with some startling hypotheses, including the idea that evolution favored depression because of its survival value and that depression is essentially a good thing. He offers his ideas as the basis of a paradigm shift. (more…)

Posted in: Book & movie reviews, Evolution, Neuroscience/Mental Health

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Animal rights activism: Petitions aren’t science

I had originally planned on writing about a different topic today, but, as is so often the case in blogging, something came up that caught my attention, much as the errant thought of a squirrel distracts Dug the Dog. It’s no big deal. My original topic is not time-sensitive, and I’ll get to it next week (that is, unless something like this happens again). In any case, my tendency towards blogging ADHD notwithstanding, the “inspiration” for this post began on Friday morning, making it timely. Let me tell you what happened, and then I’ll delve into the topic.

We all have our daily rituals, and I’m no different. When I wake up in the morning, I usually check my iPhone to see how many e-mails I’ve gotten overnight. If there’s time before I have to leave for work, I’ll frequently go through them all right then, answering ones I can answer quickly and filing for later responses those that I can’t. If I don’t have time (as in I overslept), I’ll check them whenever I get an opportunity. Last Friday, I was rather surprised to see that the little badge on the Mail app showed well over three times the usual number of messages I get overnight, even accounting for e-mail notifications of comments on the blogs and the usual smattering of mailing list messages and the odd junk spam that got through the filters. So having that many messages in my unread mail queue caught my attention. Even when a new troll shows up in the comments of one of the blogs, I usually don’t get that many notifications. I figured I’d better go and check to see what was going on right then, rather than waiting until later. What I found was something that I never would have guessed.

As odd as it seems to me now, I had apparently been targeted by a Change.org petition Animal Experimenters – JUSTIFY YOUR SCIENCE CLAIMS. (more…)

Posted in: Basic Science, Cancer, Evolution

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Tribalism and Medical Ethics

Science is intended to discover the “is”, not the “ought;” facts, not values. Science can’t tell us whether an action is moral; it can only provide evidence to help inform moral decisions. For instance, some people who believe abortion is immoral reject birth control methods that prevent implantation of a fertilized ovum on the grounds that it constitutes abortion; science can determine that a particular birth control method prevents fertilization rather than preventing implantation of a fertilized ovum. A new book, Moral Tribes: Emotion, Reason, and the Gap Between Us and Them, by Joshua Greene, provides some intriguing insights that are pertinent to medical ethics.

He thinks tribalism is the central tragedy of modern life. Evolution equipped us for cooperation within our own tribe but not for cooperation with other tribes. Cooperation with related individuals helps spread our own genes, but we are in competition with other tribes and cooperating with them might help spread their genes to the detriment of our own. It boils down to Us vs. Me and Us vs. Them. He uses the word “tribes” not in the original sense (Hutus vs. Tutsis), but to include Democrats vs. Republicans, Catholics vs. Protestants, CAM vs. science-based medicine, Arabs vs. Israelis, climate change activists vs. climate change deniers, and any other ideological or nationalistic group. (more…)

Posted in: Book & movie reviews, Critical Thinking, Evolution, Medical Ethics

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Alternative Microbiology

A man of science rises ever, in seeking truth; and if he never finds it in its wholeness, he discovers nevertheless very significant fragments; and these fragments of universal truth are precisely what constitutes science.

~ Claude Bernard.

I almost never have to search for material for this blog. The Secret always seems to provide topics. Subject matter appears unbidden out of the ether. But not this week. I enjoy deconstructing the nonsense of SCAM papers or blog entries more than any other type of blog entry. Perhaps the glee that last week’s entry provided had to be countered by some kind of cosmic balancing mechanism. Although the rational part of my mind objects to the personification of random existence, I suppose the Universe just does not want me to have that much fun two entries in a row. Probably explains why I have a viral URI and my brain has slowed almost to the point of functional inactivity. There is no shortage of SCAMs to write about, they are just not created equal in their ability to generate a passionate rant. (more…)

Posted in: Epidemiology, Evolution, Science and Medicine

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Doves, Diplomats, and Diabetes

In the past I have criticized evolutionary medicine for its tendency to rely on unverifiable “Just-So Stories,” but a new book has helped me appreciate what the best kind of evolutionary thinking can contribute to our understanding of medicine. Doves, Diplomats, and Diabetes: A Darwinian Interpretation of Type 2 Diabetes and Related Disorders by Milind Watve investigates diabetes from an evolutionary perspective, suggesting how it might have originated, why it persisted, and how it is related to survival advantages. Watve develops well-reasoned hypotheses that can be tested by examining their expected consequences. He believes it is impossible to understand metabolism without understanding behavioral ecology, and he makes a good case.

A reassessment of the evidence concerning Type II diabetes (T2D) reveals a number of paradoxes. Elevated blood glucose is the defining feature of T2D but controlling it doesn’t prevent all the complications of diabetes, and it doesn’t appear that elevated blood sugar could produce all the pathological changes of diabetes.  Insulin resistance is believed to be central to a cluster of deadly diseases in humans, but in other animals it has no adverse effects on health and even increases lifespan. Studying diabetes from an evolutionary perspective can shed light on such paradoxes. (more…)

Posted in: Basic Science, Book & movie reviews, Evolution

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It’s a part of my paleo fantasy, it’s a part of my paleo dream

There are many fallacies that undergird alternative medicine, which evolved into “complementary and alternative medicine” (CAM), and for which the preferred term among its advocates is now “integrative medicine,” meant to imply the “best of both worlds.” If I had to pick one fallacy that rules above all among proponents of CAM/IM, it would have to be either the naturalistic fallacy (i.e., that if it’s natural—whatever that means—it must be better) or the fallacy of antiquity (i.e., that if it’s really old, it must be better). Of course, the two fallacies are not unrelated. In the minds of CAM proponents, old is more likely to have been based on nature, and the naturalistic fallacy often correlates with the fallacy of antiquity. Basically, it’s a rejection of modernity, and from it flow the interest in herbalism, various religious practices rebranded as treatments (thousands of years ago, medicine was religion and religion was medicine—the two were more or less one and physicians were often priests as well), and the all-consuming fear of “toxins,” in which it is thought that the products of modernity are poisoning us.

Yes, there is a definite belief underlying much of CAM that technology and pharmaceuticals are automatically bad and that “natural” must be better. Flowing from that belief is the belief that people were happier and much healthier in the preindustrial, preagricultural past, that cardiovascular disease was rare or nonexistent, and that cancer was seldom heard of. Of course, it’s hard not to note that cancer and heart disease are primarily diseases of aging, and life expectancy was so much lower back in the day that a much smaller percentage of the population lived to advanced ages than is the case today. Even so, an implicit assumption among many CAM advocates is that cardiovascular disease is largely a disease of modern lifestyle and diet and that, if modern humans could somehow mimic preindustrial or, according to some, even preagricultural, lifestyles, that cardiovascular disease could be avoided. Not infrequently, evolutionary and genomic arguments are invoked, claiming that the estimated 10,000 years since the dawn of human agriculture is not a sufficiently long period of time for us to have evolved to handle diets rich in grains and meats and that we are “genetically wired” to exist on a diet like those of our paleolithic hunter-gatherer ancestors. For instance, in 2004, James H. O’Keefe Jr, MD and Loren Cordain, PhD wrote an article in the Mayo Proceedings entitled Cardiovascular Disease Resulting From a Diet and Lifestyle at Odds With Our Paleolithic Genome: How to Become a 21st-Century Hunter-Gatherer that asserted in essence, just that. Over the last decade, Cordain has become the most prominent promoter of the so-called “Paleo diet,” having written The Paleo Diet: Lose Weight and Get Healthy by Eating the Foods You Were Designed to Eat and multiple other books advocating a paleolithic-mimetic diet as the cure for what ails modern humans. Meanwhile, diets thought to reflect what our hunter-gatherer ancestors ate, such as the Paleo Diet consisting largely of animal and fish that can be hunted and fruits and vegetables that can be foraged for in the wild, have been promoted as a near-panacea for the chronic diseases of aging, such as cardiovascular disease and cancer.

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Posted in: Evolution, History, Nutrition

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Gender Differences and Why They Don’t Matter So Much

Several incidents have recently created divisions within the skeptical community.  The latest one was over a casual comment Michael Shermer made in an online talk show. He was asked why the gender split in atheism was not 50/50, “as it should be.” He said he thought it probably was 50/50, and suggested that the perception of unequal numbers might be because attending and speaking at atheist conferences was more of “a guy thing.” They might have asked him to explain what he meant. They didn’t. He didn’t mean to say it was encoded in the male DNA. He was simply recognizing a reality of our society: male/female interests and behavior tend to differ due to all sorts of cultural influences. Among other things, women might find it more difficult to attend meetings because of lower incomes and the need to arrange for babysitters. Watching sports on TV with other guys and beer is a guy thing too, but not because it’s hardwired into the male brain. It’s a guy thing because of customs and attitudes in our society.  And it certainly doesn’t mean women are less capable or that societal influences can’t be overcome.

Nevertheless, Ophelia Benson assumed Shermer meant:

that women are too stupid to do nontheism. Unbelieving in God is thinky work, and women don’t do thinky, because “that’s a guy thing.”

That’s not what he meant. It’s not fair to judge him by one off-the-cuff remark. His record stands for itself: there is not a hint of sexism in his writings and he has always fully acknowledged women’s intelligence and their ability to think critically.

In a rebuttal article, Shermer quoted me:

I think it is unreasonable to expect that equal numbers of men and women will be attracted to every sphere of human endeavor. Science has shown that real differences exist. We should level the playing field and ensure there are no preventable obstacles, then let the chips fall where they may.

PZ Myers called this “a sexist remark.” (more…)

Posted in: Evolution, General, History

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Epigenetics: It doesn’t mean what quacks think it means

Epigenetics. You keep using that word. I do not think it means what you think it means.

I realize I overuse that little joke, but I can’t help but think that virtually every time I see advocates of so-called “complementary and alternative medicine” (CAM) or, as it’s known more commonly now, “integrative medicine” discussing epigenetics. All you have to do to view mass quantities of misinterpretation of the science of epigenetics is to type the word into the “search” box of a website like Mercola.com or NaturalNews.com, and you’ll be treated to large numbers of articles touting the latest discoveries in epigenetics and using them as “evidence” of “mind over matter” and that you can “reprogram your genes.” It all sounds very “science-y” and impressive, but is it true?

Would that it were that easy!

You might recall that last year I discussed a particularly silly article by Joe Mercola entitled How your thoughts can cause or cure cancer, in which Mercola proclaims that “your mind can create or cure disease.” If you’ve been following the hot fashions and trends in quackery, you’ll know that quacks are very good at leaping on the latest bandwagons of science and twisting them to their own ends. The worst part of this whole process is that sometimes there’s a grain of truth at the heart of what they say, but it’s so completely dressed up in exaggerations and pseudoscience that it’s really, really hard for anyone without a solid grounding in the relevant science to recognize it. Such is the case with how purveyors of “alternative health” like Joe Mercola and Mike Adams have latched on to the concept of epigenetics.
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Posted in: Basic Science, Cancer, Evolution, Neuroscience/Mental Health

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Worms, Germs, and Dirt: What Can They Teach Us About Allergies and Autoimmune Diseases?

Whipworms in the intestine

Whipworms in the intestine. Click to enlarge.

Humans evolved in an environment where they were exposed to animals, dirt, and a variety of pathogens and parasites. Our immune systems evolved to cope with that environment. Now most of us live in a different environment, with safe drinking water, flush toilets, food inspection, immunizations, and public sanitation. This means that we are far less likely than our ancestors to die of infectious diseases or to harbor intestinal worms. But it seems that the cleaner we get, the more likely we are to suffer from allergies and autoimmune diseases. One hypothesis is that our immune systems evolved to require early challenges by parasites and pathogens in order to develop properly. A hygienic environment fails to give our immune system the exercise it needs, resulting in imbalances and malfunctions.

The hygiene hypothesis was first proposed to explain observations like these:

  • Hay fever and allergies were less common in large families where children were presumably exposed to more infections through their siblings.
  • Polio attack rates were higher in high socioeconomic groups than in lower ones.
  • Allergies and many other diseases were less common in the developing world.

Investigation of these and other phenomena is contributing to a better understanding of the immune system, which is a good thing. At the same time, it has led some people to deliberately infect themselves with intestinal worms in an attempt to cure their allergies and autoimmune diseases, which may not be such a good thing. These treatments are far from ready for prime time, are risky, and they have a high yuck factor. The very idea of deliberately infecting yourself with worms is unpalatable, and finding wiggly live creatures in your stool or passing a 20 foot tapeworm are not generally considered to be pleasant experiences.  (more…)

Posted in: Book & movie reviews, Epidemiology, Evolution

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780.6

You can tell what a doctor does for a living by the ICD-9 codes they have memorized. There is an ICD-9 code for nearly every medical condition. Weightlessness is 994.9. Must be there for NASA, I have yet to see a weightless patient. Decapitation by guillotine is E978. There, I suppose, in case Marat returns from the dead. There is an ICD-9 code for the initial visit after being sucked into jet engine (V9733XA) and one for subsequent visits (V9733XD). Why do I suspect V9733XD has yet to be used?

780.6 is my personal favorite. Fever. All my patients have fever and 780.6 was certainly the first ICD-9 code I committed to memory. I have an endless interest in fever and after last Fridays post I thought I would toss in my two cents worth. I will remind my readers that I am an adult ID doctor (who I treat, not necessarily how I behave) and unless specifically mentioned, all that follows applies to those who can legally drink, vote and serve in the military.

98.6 F. It is not normal body temperature. Well it is. But it is not. 98.6 F as average body temperature is an enduring medical myth. (more…)

Posted in: Basic Science, Evolution, History, Science and Medicine

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