Frederick Crews is writing about selective serotonin reuptake inhibitors” (SSRIs):
Hence the importance of David Healy’s stirring firsthand account of the SSRI wars, Let Them Eat Prozac. Healy is a distinguished research and practicing psychiatrist, university professor, frequent expert witness, former secretary of the British Association for Psychopharmacology, and author of three books in the field. Instead of shrinking from commercial involvement, he has consulted for, run clinical trials for, and at times even testified for most of the major drug firms. But when he pressed for answers to awkward questions about side effects, he personally felt Big Pharma’s power to bring about a closing of ranks against troublemakers. That experience among others has left him well prepared to puncture any illusions about the companies’ benevolence or scruples.
. . .
The most gripping portions of Let Them Eat Prozac narrate courtroom battles in which Big Pharma’s lawyers, parrying negligence suits by the bereaved, took this line of doubletalk to its limit by explaining SSRI-induced stabbings, shootings, and self-hangings by formerly peaceable individuals as manifestations of not-yet-subdued depression. As an expert witness for plaintiffs against SSRI makers in cases involving violent behavior, Healy emphasized that depressives don’t commit mayhem. But he also saw that his position would be strengthened if he could cite the results of a drug experiment on undepressed, certifiably normal volunteers. If some of them, too, showed grave disturbance after taking Pfizer’s Zoloft—and they did in Healy’s test, with long-term consequences that have left him remorseful as well as indignant—then depression was definitively ruled out as the culprit.
Healy suspected that SSRI makers had squirreled away their own awkward findings about drug-provoked derangement in healthy subjects, and he found such evidence after gaining access to Pfizer’s clinical trial data on Zoloft. In 2001, however, just when he had begun alerting academic audiences to his forthcoming inquiry, he was abruptly denied a professorship he had already accepted in a distinguished University of Toronto research institute supported by grants from Pfizer. The company hadn’t directly intervened; the academics themselves had decided that there was no place on the team for a Zoloft skeptic.
That doesn’t make the research institute look so good, although maybe there’s another side to the story.
Hey, did he just say what I think he said???
Undeterred, Healy kept exposing the drug attorneys’ leading sophistry, which was that a causal link to destructive behavior could be established only through extensive double-blind randomized trials—which, cynically, the firms had no intention of conducting. In any case, such experiments could have found at best a correlation, in a large anonymous group of subjects, between SSRI use and irrational acts; and the meaning of a correlation can be endlessly debated. In contrast, Healy’s own study had already isolated Zoloft as the direct source of his undepressed subjects’ ominous obsessions.
Thanks partly to Healy’s efforts, juries in negligence suits gradually learned to be suspicious of the “randomized trial” shell game. . . .
I agree that randomized trials aren’t the whole story, and I’ll further agree that maybe we statisticians overemphasize randomized trials. But, but, . . . if you do do a randomized trial, and there are no problems with compliance, etc., then, yes, the correlation does imply causation! That’s the point of the randomized design, to rule out all the reasons why observational results can be “endlessly debated.”
The New York Review of Books needs a statistical copy editor! I don’t know anyone there (and I don’t know Crews), but maybe someone can pass the message along. . . .
P.S. Maybe I’m being too hard on Crews, who after all is a literary critic, not a statistician. I assume he wrote this thing about correlation and causation because he misinterpreted what some helpful statistician or medical researcher had to say. Sort of like how I might sound foolish if I tried to make some pronouncement about Henry James or whatever.
P.P.S. Typo fixed (thanks, Sebastian).