Bias is one of the most effective charges a cross-examiner can make. He who pays the piper calls the tune is the common sense maxim. But the rules of evidence do not exclude biased testimony. They permit exposure of bias to the fact-finder. Federal evidence rule 702 , like its state analogs, compels exploration of expert opinion testimony's basis in reason before it can be admitted. And the rules of discovery provide powerful means to identify, explore, and expose bias - the subpoena, the deposition, the demand for production of documents .
Plaintiffs in Accutane (isotretinoin) product liability cases face difficult proof problems: their depressed clients (or their survivors) claim that their emotional state, already troubled, was worsened substantially by the drug. The public health survey evidence marshaled is a piece of a circumstantial evidence argument. But such proofs may be seen as suggestive only and lack persuasive force for many. Plaintiffs' lawyers therefore have sought to establish that the drug induces a physiological process which so aggravates depression that patients have been driven to suicidal acts that otherwise would not have occurred.
There is a lively debate about such a study funded by plaintiffs' lawyers in part, which was published HERE in the American Journal of Psychiatry. The abstract reports the plaintiff-favorable result:
OBJECTIVE: Although there have been case reports suggesting a relationship between treatment with the acne medication isotretinoin and the development of depression and suicide, this topic remains controversial. In order for isotretinoin to cause depression, it must have an effect on the brain; however, the effects of isotretinoin on brain functioning in acne patients have not been established. The purpose of this study was to assess the effects of isotretinoin on brain functioning in acne patients. METHOD: Brain functioning in adults was measured with [18F]fluorodeoxyglucose positron emission tomography before and after 4 months of treatment with isotretinoin (N=13) or an antibiotic (N=15). RESULTS: Isotretinoin but not antibiotic treatment was associated with decreased brain metabolism in the orbitofrontal cortex (–21% change versus 2% change for antibiotic), a brain area known to mediate symptoms of depression. There were no differences in the severity of depressive symptoms between the isotretinoin and antibiotic treatment groups before or after treatment. CONCLUSIONS: This study suggests that isotretinoin treatment is associated with changes in brain functioning.Industry-oriented critics, like the blogger/neuroloigst Barbara Martin at Pathophilia, find that such evidence presents a "disturbing" conflict of interest. But the the Appellate Division of the Superior Court of New Jersey in Palazzolo v. Hoffman LaRoche last month held that such testimony may be admissible to prove "general causation" - that the drug may play a role in causing depression.
Torts scholar William Childs has argued that the focus on methodology mandated by the landmark Daubert opinion in 1992 undercuts the assertion that such studies are impermissibly biased and should not be admissible in court. William G. Childs, "The Overlapping Magisteria of Law and Science: When Litigation and Science Collide" (March 22, 2006). bepress Legal Series. Working Paper 1178.
For more on the issues of bias and expert witnesses, check out Prof. Childs post on Torts Prof Blog HERE
Thanks to Pathophilia for the graphic.