A recently published epidemiological study in JAMA Pediatrics looked at the association between induction and enhancement of labor and the risk of autism. The researchers found a positive association, especially with males. The study has been variously reported in the popular press with causal interpretations not justified by the data.
The study itself is very robust – the authors looked at 625,042 live births, including 5,500 children with a diagnosis of autism. They found:
Compared with children born to mothers who received neither labor induction nor augmentation, children born to mothers who were induced and augmented, induced only, or augmented only experienced increased odds of autism after controlling for potential confounders related to socioeconomic status, maternal health, pregnancy-related events and conditions, and birth year. The observed associations between labor induction/augmentation were particularly pronounced in male children.
Although this is a large study, it is one study, and so the correlation needs to be independently confirmed. But if we assume the correlation is accurate, the next question is – what is the arrow of causation? Observational studies can only indicate an association. By themselves they cannot prove causation, although multiple observational studies may be able to triangulate to the most likely causal interpretation. (more…)
Mercury in unequivocally a neurotoxin. It is especially damaging to the developing brain. But it’s the dose that makes the toxin, and so a low enough exposure even to something known to be potentially harmful may not be. Further, the body has mechanisms for dealing with toxins, and toxins in the body may not be reaching the cells they can potentially damage in significant amounts. Therefore if we want to know if a potential toxin is actually causing any harm to people we need to do some type of epidemiological study – correlating exposure to possible adverse outcomes. All the studies in petri dishes and with cell cultures just won’t answer the question of harm.
The question of whether or not mercury in vaccines has caused neurological harm, specifically autism, has been largely answered. Numerous studies have shown no association between the amount of mercury exposure from vaccines and the risk of developing autism. A separate mercury-related question, however, is whether or not there is any risk of harm from mercury exposure from seafood. Mercury is methylated by bacteria into methymercury, and through them gets into the food chain in the oceans. Fish that eat other fish then concentrate the mercury in their tissues, and so predatory fish and sea mammals tend to have high concentrations of methymercury.
This has led to some precautionary recommendations, including that pregnant women should not eat tuna or other fish with high mercury levels. This makes sense, but what is the actual risk? The precautionary principle can also cut both ways. Fish contain many high-quality nutrients important for a developing brain, such as polyunsaturated fatty acids. Removing this food source from the diet of pregnant women may have unintended negative consequences.
In the last decade or so there has been increasing research into non-invasive brain stimulation techniques for a variety of conditions. These include transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), random noise stimulation (tRNS), and transcranial magnetic stimulation (TMS). These techniques alter the excitability of neurons in the brain, seem to have an effect on plasticity (the ability to form new connections), and can modulate the activity of brain networks.
Overall the current research is preliminary but encouraging. Many of the details of exactly how to apply this new technology, however, are still being worked out. One recent review summarizes this complexity:
tDCS can be used to manipulate brain excitability via membrane polarisation: cathodal stimulation hyperpolarises, while anodal stimulation depolarises the resting membrane potential, whereby the induced after-effects depend on polarity, duration and intensity of the stimulation. A variety of other parameters influence tDCS effects; co-application of neuropharmacologically active drugs may most impressively prolong or even reverse stimulation effects. Transcranial alternating stimulation (tACS) and random noise stimulation (tRNS) are used to interfere with ongoing neuronal oscillations and also finally produce neuroplastic effects if applied with appropriate parameters.
Finding a simple fix for complex problems is highly appealing, which drives a persistent market in simple fixes, whether or not they are actually effective. The growing “brain training” industry is an example of this – the concept being that performing simple tasks, such as playing particular games, can have wide-ranging cognitive benefits. Unfortunately the evidence has not been kind to this notion.
Related to the brain training concept is auditory integration training. One permutation of this, the Tomatis Method, describes it this way:
The sound message is correctly heard but poorly analyzed in an emotional framework. The brain protects itself by constructing barriers that can result in the development of various disorders.
You can do the listening sessions repeatedly by using specially designed devices that stimulate the brain and progressively help it more effectively analyze the sensory message.
Your ear is not used only for hearing. It also stimulates your brain and establishes your balance. Well-tuned listening is therefore an essential component for promoting personal development.
This is a common approach to marketing such therapies – argue that one factor is a dominant cause of a host of problems, describe the method for addressing that one factor, which then leads to a happy, healthy, fulfilling life. This marketing formula appears well established. (more…)
Editor’s note: This is an extra “bonus” post. Basically, it’s a revised version of a post I did at my not-so-super-secret-other-blog last week. The issue, however, has disturbed me so much that I felt it appropriate to post it to SBM as well. Fear not. There will be a new post by yours truly on Monday.
Sometimes, in the course of blogging, I come across a story that I don’t know what to make of. Sometimes, it’s a quack or a crank taking a seemingly science-based position. Sometimes it’s something out of the ordinary. Other times, it’s a story that’s just weird, such that I strongly suspect that something else is going on but can’t prove it. So it was a few months ago when I came across the story of Alex Spourdalakis, a 14-year-old autistic boy who became a cause célèbre of the antivaccine crank blog Age of Autism.
I first noticed the story in early March when perusing AoA and came across a post by Lisa Goes entitled Day 19: Chicago Hospital Locks Down Autistic Patient. In the post was a shocking picture of a large 14-year-old boy in a a hospital bed in four-point restraints. He was naked, except for a sheet covering his genitals. A huge gash was torn in the bedsheet, revealing the black vinyl of the hospital bed beneath. The boy’s name, we were informed, was Alex Spourdalakis. Further down in the post was another, equally shocking, picture of Alex that, according to Goes, showed severe dermatitis on Alex’s back due to the hospital sheets. The photos shocked me for two reasons. First, if the story was as advertised (something always to be doubted about any story posted at AoA), for once I thought that I might be agreeing with Goes and thinking that AoA was actually doing a good thing, as disconcerting as that possibility was to me. Second, however, I was extremely disturbed by the publication of such revealing photos of the boy. Undoubtedly, Alex’s mother must have given permission. What kind of mother posts pictures like that of her son for all the world to see? Then there appeared a Facebook page, Help Support Alex Spourdalakis, which pled for readers to help the Spourdalakis family.
As I said, something just didn’t seem right at the time.
It’s frustrating to read yet another story of the process of developing a potential new medical treatment derailed by the current infrastructure of quackery that we have in this and other countries. This is one of the unmeasurable harms that results when pseudoscience is given regulatory, academic, and professional legitimacy. The press then celebrates the nonsense that results.
The basic story is often the same, with a few variations. First, however, let me describe what should happen when someone comes up with an idea for a new medical treatment.
Background research – The first step, whether the innovator is within or without the medical community, is to familiarize oneself with existing research. Is the idea plausible, has it been investigated before, are there any similar treatments that can act as a guide to predicting how this new treatment will work?
The fifth edition of the Diagnostics and Statistical Manual (DSM-5) was recently released. This is the standard reference of mental disorders and psychiatric illnesses released by the American Psychiatric Association (APA).
As with previous editions there is a great deal of discussion and wringing of hands over the details – which disorders were created or eliminated. For example hoarding is now considered its own disorder, rather than part of obsessive compulsive disorder (it has its own reality TV show, why not its own DSM diagnosis?).
This time around, however, the debate over the DSM goes much deeper than the particulars of specific diagnoses. The real debate is about the very existence of the DSM – its validity and utility. While this discussion is nothing new, it has taken on an unprecedented dimension with the rejection of the DSM by the National Institutes of Mental Health (NIMH). Director Thomas Insel wrote:
The goal of this new manual, as with all previous editions, is to provide a common language for describing psychopathology. While DSM has been described as a “Bible” for the field, it is, at best, a dictionary, creating a set of labels and defining each. The strength of each of the editions of DSM has been “reliability” – each edition has ensured that clinicians use the same terms in the same ways. The weakness is its lack of validity. Unlike our definitions of ischemic heart disease, lymphoma, or AIDS, the DSM diagnoses are based on a consensus about clusters of clinical symptoms, not any objective laboratory measure. In the rest of medicine, this would be equivalent to creating diagnostic systems based on the nature of chest pain or the quality of fever. Indeed, symptom-based diagnosis, once common in other areas of medicine, has been largely replaced in the past half century as we have understood that symptoms alone rarely indicate the best choice of treatment.
A correspondent asked me to look into the GAPS diet. I did. I was sorry: it was a painful experience. What a mishmash of half-truths, pseudoscience, imagination, and untested claims!
GAPS stands for Gut and Psychology Syndrome. It is the invention of Dr. Natasha Campbell-McBride. According to her, a wide variety of health problems can be traced to a single cause: an imbalance of gut microbes. She cites ancient wisdom: Hippocrates said all diseases begin in the gut. She says science confirmed that wisdom when it discovered that 90% of all cells and all genetic material in the human body belongs to the gut flora. She says the modern world poses many dangers for the gut flora, and once it is damaged, the health of the whole body enters a downward slide towards disease. She claims that autism and ADD, OCD, schizophrenia, epilepsy, depression, and numerous other ailments are all digestive disorders. (more…)
In his first book, On Being Certain: Believing You Are Right Even When You’re Wrong, neurologist Robert Burton showed that our certainty that we are right has nothing to do with how right we are. He explained how brain mechanisms can make us feel even more confident about false beliefs than about true ones. Now, in a new book, A Skeptic’s Guide to the Mind: What Neuroscience Can and Cannot Tell Us About Ourselves, he investigates the larger question of how a brain creates a mind. There is no alternative to the scientific method for studying the physical world, but Burton thinks there are essential limitations to science’s ability to investigate conundrums like consciousness and free will. Brain scientists fall into error because:
…our brains possess involuntary mechanisms that make unbiased thought impossible yet create the illusion that we are rational creatures capable of fully understanding the mind created by these same mechanisms.
He has a bone to pick with neuroscientists. They are discovering fascinating information, but their interpretations often go beyond what the data can really tell us. They often draw questionable conclusions from imaging studies that could have other explanations. (more…)
Websites such as Luminosity.com make some bold promises about the effectiveness of computer-based brain-training programs. The site claims:
“Harness your brain’s neuroplasticity and train your way to a brighter life”
“Your brain’s abilities are unique. That’s why your Personalized Training Program adapts to fit your brain and your life goals.”
“Just 10 hours of Lumosity training can create drastic improvements. Track your own amazing progress with our sophisticated tools.”
Wow – in just 10 hours I can become smarter by playing fun video games personalized to my brain. I’m a huge fan of video games, and I would love to justify this hobby by saying that I’m training my brain while I play, but what does the scientific evidence have to say about such claims?
Not surprisingly, the published evidence is complex and mixed.