Wednesday, June 8, 2011

Is the credibility of Emory neurologist Helen Mayberg in question? You judge

A few weeks ago, I blogged about the strange case of Dr. Helen Mayberg, a neurologist at Emory University who has testified in more death penalty cases in recent years than almost any other doctor in the country. I highlighted Mayberg's lucrative and lethal (she always testifies for the prosecution who are pushing for the death penalty) sideline as an example of why the National Institutes of Health should adopt stricter conflict of interest guidelines that would require universities to more fully disclose the extent of their researchers' financial conflicts of interest.

At the time, I quoted a prominent neurologist who said that Mayberg goes to considerable lengths to rebut defense experts, often introducing inaccurate information and contradicting herself in the process. Since then, I have received additional information about her testimony in one particular death penalty case that appears to buttress such accusations. Indeed, critics say that her testimony indicates a level of hypocrisy and willingness to dissemble that should concern officials at the NIH, where Mayberg is principal investigator of several major multi-million-dollar research grants.

First some background. As I've blogged about here, Mayberg was recruited to Emory University by former psychiatry kingpin Charles Nemeroff and soon became involved in a major conflict of interest controversy with Nemeroff when they both failed to disclose significant financial ties to a medical device company in a positive paper they wrote about the company's patented technique. After Nemeroff was forced to step down as chief of psychiatry at Emory (for this and other failures to disclose), he departed Emory for the University of Miami. And lo and behold, Mayberg, who is not a psychiatrist and has never treated patients in clinical practice, became principal investigator of two major NIMH studies Nemeroff used to lead: the mood and anxiety disorders initiative, a collaboration between NIMH (which put up $2.1 million last year alone) and GlaxoSmithKline, to develop a new generation of antidepressants, and another $1.8 million study called predictors of antidepresssant treatment response.

As the principal investigator of such large, taxpayer-funded studies, Mayberg's credibility should be above reproach. However, according to transcripts, she has testified under oath in direct contradiction of her own statements in published research papers. In one particular death penalty case, a neurologist for the defense testified that PET scans taken of the defendant, a guy convicted of murder by the name of Erick Virgil Hall, showed that he had decreased functioning in an area of the brain associated with impulse control and aggressive behavior. Dr. James Merikangas, a clinical professor of psychiatry and at the George Washington School of Medicine, used the neuroimaging results, together with a comprehensive review of the defendant's social and medical history and a physical examination, to conclude that Hall had brain damage that should be allowed as mitigating evidence in his case. Merikangas was careful not to say that the decreased brain functioning found in the PET scan explained Hall's violent behavior, only that there was evidence of brain damage that may have impaired his judgment. (Such mitigating evidence is often introduced in an effort to take prisoners off death row and convert their sentence to a life in prison).

In her 2007 testimony in the Hall case, Mayberg derided the value of PET scans in showing brain damage, saying that "the use of PET scans for the clinical diagnosis and treatment of individual patients is extremely limited." She concluded that PET and functional neuroimaging scans cannot be used for diagnostic purposes or to quantify "residual effects of past traumatic brain injury."

However, Mayberg herself has used PET scans to diagnose depression and evaluate the response of depressed patients to deep brain stimulation, a surgical technique that she developed and patented and continues to promote as a valid treatment for depressed patients who have not responded to drugs; I've blogged about the controversial nature of her work here. In several papers Mayberg published about her research with deep brain stimulation, she discussed the value of using PET scans for this purpose. In one 1990 paper, for instance, she said that a PET scan "showed hypometabolism [decreased brain functioning] in the right lateral basotemporal region in all three patients." In another 2007 paper, she used PET scans to assert that "non-response to treatment and previous depressive episodes were associated with a higher degree of age-dependent hypometabolism in the rostral and anterior cingulate cortex." In yet another summary of one of her NIH-funded studies, she says she will use PET scans to assess the response of patients to different treatments. In these and other published articles, Mayberg herself is drawing cause and effect relationships between brain abnormalities and specific psychological conditions.

As Merikangas points out in his affidavit, Mayberg is well aware of the importance of neuroimaging in a forensic setting. In another 2007 paper, Mayberg concluded:
"In sum, neuroimaging evidence has become an increasingly important tool of proof in criminal and civil cases in the United States. Although subject to the constraints of reliability and relevance, results of neuroimaging scans can and do help courts to understand the nature, causes and behavior implications of injuries to the brain."
Indeed, a recent study cited in the New York Times affirmed that a highly sensitive functional type of magnetic resonance imaging found evidence of brain injuries in veterans injured in Iraq or Afghanistan that was too subtle to be detected by standard MRI scans.

To be fair, Mayberg testified in the Hall case three years before this new study came out. However, by 2007, plenty of research evidence existed showing that PET and other neuroimaging scans could detect key changes in brain functioning. In his affidavit, Merikangas cites three papers published in 2005 and 2007 indicating decreased brain functioning picked up by PET scans in areas implicated in aggressive and violent behavior.

Mayberg, Merikangas says, is simply ignoring the peer-reviewed literature on this subject. He concludes that her testimony in the Hall case is both misleading and deceptive. Now, Mayberg is at liberty to consult for and testify in whatever legal proceedings she elects to, as long as she fully discloses these conflicts of interest (which some would argue she hasn't). But as someone who is in charge of millions of dollars of taxpayer money, her word should be inviolate. It's kind of analogous to what's going on with Anthony Weiner and tweetgate. Given his sorry track record of lying to the American public, Rep. Weiner (NY) should probably resign his post in Congress, and in my view, we should hold federally funded researchers to the same high standard of credibility.

Footnote: Erich Hall is still on death row.

1 comment:

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