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Archive for Neuroscience/Mental Health

Do Antidepressants Work? The Effect of Publication Bias

A recent meta-analysis of the most commonly prescribed antidepressant drugs raises some very important questions for science-based medicine. The study: Initial Severity and Antidepressant Benefits: A Meta-Analysis of Data Submitted to the Food and Drug Administration, was conducted by Irving Kirsch and colleagues, who reviewed clinical trials of six antidepressants (fluoxetine, venlafaxine, nefazodone, paroxetine, sertraline, and citalopram). They looked at all studies submitted to the FDA prior to approval, whether published or unpublished. They found:

Drug–placebo differences in antidepressant efficacy increase as a function of baseline severity, but are relatively small even for severely depressed patients. The relationship between initial severity and antidepressant efficacy is attributable to decreased responsiveness to placebo among very severely depressed patients, rather than to increased responsiveness to medication.

The press has largely reported this study as showing that “antidepressants don’t work” but the full story is more complex. This analysis certainly has important implications for how we should view the body of evidence for these antidepressants. It also illuminates the possible role of publication bias in the body of scientific literature – something that has far ranging implications for science-based medicine.

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Posted in: Clinical Trials, Neuroscience/Mental Health, Pharmaceuticals, Science and Medicine

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Science by press release: A helmet to fight Alzheimer’s disease?

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Recently, I’ve had a number of people bring to my attention a news story that has apparently been sweeping the wire services and showing up in all sorts of venues. It is, on its surface, a story of hope, hope for the millions of elderly (and even the not-so-elderly) who are or will be afflicted by that scourge of the mind, memory, and personality, Alzheimer’s disease. This disease is one of the most feared of diseases. A progressive and fatal disease of the brain, it robs a person of his memory and personality, until he no longer recognizes loved ones and becomes too demented to care for himself. The pathophysiology involves the accumulation in the brain of a protein known as β-amyloid, which forms plaques outside of cells, while neurofibrillary tangles believed to be due to the hyperphosphorylation of a protein known as tau develop in dying cells. The exact mechanism by which neuron death occurs is not fully understood, but over time this process leads to a decrease in the amount of gray matter in the cortex. There is no known cure, and the current treatments that we have result in at best a modest delay of the inevitable dementia that accompanies progression of the disease.

Given this grim backdrop and the general aging of the population in developed nations, it is expected that there will be a large increase in the number of people developing Alzheimer’s disease over the next few decades. Naturally, this provides a great deal of incentive to develop more effective treatments. Not surprisingly, sometimes the treatments proposed may sound somewhat outlandish and may even be somewhat outlandish. The treatment about which people were e-mailing me falls into this category, and I haven’t decided yet whether it’s science or pseudoscience. It could be legitimate. What I do know, however, is that I don’t like the way its inventors are promoting it by press conference before any evidence of its clinical efficacy in humans has been accepted by a peer-reviewed publication, leading to a flurry of stories about a new possible “miracle cure” for Alzheimer’s disease grounded in not a lot of science. I’m referring, of course, to the “Alzheimer’s helmet” developed by Dr. Gordon Dougal and his colleagues Dr. Paul Chazot and Abdel Ennaceur at Durham University. Dr. Dougal is a director of Virulite, a medical company based in County Durham in the U.K. Here’s a widely cited article from the Daily Mail that describes the device:
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Posted in: Basic Science, Medical Ethics, Neuroscience/Mental Health, Science and Medicine, Science and the Media

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Itching and the Imaginary Passenger Brake

The press and government agencies ally to shine a disproportionate amount of publicity on false and improbable medical ideas. (Danger: Congressmen and reporters at work.)

The latest was a press release from either the Centers for Disease Control (and prevention? – I’ll get to the “prevention” part later,) or from Kaiser-Permanente Medical Group. Three Bay Area newspapers carried simultaneous articles. The articles announced a new, $338,000 CDC/Permanente study of something they call “Morgellon’s disease.” I say they call it that because what they are describing is not what was originally described as “Morgellon’s,” but what is most likely a form of somatiform illness – delusional parasitosis, or neurodermatitis.

What is Morgellon’s and why is CDC funding Kaiser/Permanente with $338,000 to study it? I was never taught about anything called Morgellon’s, and althoughI had practiced medicine for forty years, I still had not known of it until several years ago when a group of affected San Francisco patients and R L Stricker MD, were reported as having a number of cases of it.

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Posted in: General, Neuroscience/Mental Health, Science and Medicine

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Mercury in vaccines as a cause of autism and autism spectrum disorders (ASDs): A failed hypothesis

Blogging on Peer-Reviewed ResearchOne of the most pernicious medical myths of recent years has been the claim, promulgated by a subgroup of parents of autistic children and facilitated by scientists of dubious repute, that somehow the mercury in the thimerosal (ethyl mercury) preservative used in common childhood vaccines in the U.S. until early 2002 causes autism. Although it had been percolating under the radar of most parents and scientists for several years before, this belief invaded the national zeitgeist in a big way in 2005, beginning with the publication of a book by journalist David Kirby entitled Evidence of Harm: Mercury in Vaccines and the Autism Epidemic: A Medical Controversy. The fires of hysteria were stoked even higher by Robert F. Kennedy, Jr., who published a truly twisted and misleading piece of pseudojournalism and pseudoscience published simultaneously in Rolling Stone and on Salon.com entitled Deadly Immunity. Relying primarily on quote-mining of the transcripts of both a conference held Atlanta by the CDC to discuss the question of whether autism is related to thimerosal in vaccines and an Institute of Medicine report on vaccines while simultaneously misrepresenting the results of two studies by Verstaeten et al to paint a false picture of a government coverup, RFK Jr. almost single-handedly managed to stoke fears that vaccines were causing an “epidemic of autism.”

I say “almost” single-handedly, because, unfortunately, he had help. Relying on the dubious research of a variety of investigators, such as the father-and-son team of Dr. Mark Geier and David Geier, whose prodigious output of badly designed studies emanating from a lab in their home in suburban Maryland, done using a rubberstamp institutional review board stacked with friends and cronies to approve the studies, and published for the most part in non-peer-reviewed journals, activists loudly insisted that mercury in vaccines was the cause of most autism. Others claiming to demonstrate this link include Boyd Haley, a chemist from the University of Kentucky, and a few other vocal scientists and advocates, who claim that autism is, in essence, mercury poisoning. Facilitating the dissemination of this message were reporters such as David Kirby, activists such as Robert F. Kennedy, Jr., and media personalities such as Don Imus. Indeed, some activists claimed that some vaccines were “poisoning” our children, even going so far as show photos of autistic children with the label “mercury-poisoned“ underneath them on placards held aloft at protest rallies. They made quite a splash then, and still do to a lesser extent even today. There’s just one problem.
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Posted in: Dentistry, Neuroscience/Mental Health, Public Health, Science and the Media, Vaccines

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