Jerry Coyne is a professor in the Department of Ecology and Evolution at the University of Chicago, a leading critic of creationism and author of “Why Evolution is True” (amazon link), which is a lucid overview of the evidence for evolution. He also maintains a blog with the same name. Prof. Coyne is a pretty rational person, but being rational in one area is not a guarantee that one is rational in another and it is really easy to get sucked in to science denialism. Classic examples of this is people like Peter Duesberg, a member of the National Academy of Sciences, who is the father of HIV/AIDS denialism. This analogy does not seem fair, but perhaps a better one is Coby of A Few Things Ill-Considered, whose How To Talk To A Climate Skeptic is one of the best resources available against global warming denialists. Unfortunately Coby bought into the anti-fluoridation conspiracy, mostly because his dad had written a book about it. I fear that Dr. Coyne has made a similar slip-up.
In a similar turn of events, Jerry Coyne has recently bought into the anti-psychiatry madness of Angell, Kirsch, Whitaker and Carlat. Angell, a microbiologist and former editor of the NJEM reviewed the others books in New York Review of Books. It is scary to read Prof. Coyne’s summary/discussion, mostly because it repeats the same old falsehoods about psychiatry, SSRIs and Big Pharma, almost precisely following the same denialist debating tactics we all know far too well. Because of this, it is a chilling read and had this been done by any other random person on the internet I probably would not have bothered, but it feel it is my duty to correct Prof. Coyne’s misconceptions because I shared many of his other values and positions and because he has relatively high authority in the skeptic community. It would be very unfortunate if this was the beginning to his siding into denialism, not just for himself, but for his readers and the public. No one wants this to happen.
The scary part is that Prof. Coynes summary/discussion broadly and specifically mirrors most arguments put forward by HIV/AIDS denialists: there is the conspiracy by pharmaceutical companies and doctors to make more profits, the notion that treatments do not work but are in fact dangerous, that diagnostic criteria for the condition are arbitrary and differs in time and place etc. and this great irony will be a recurring theme in the following criticism. To clarify, I am not a psychologist or psychiatrist, so don’t take my word at it, but evaluate the arguments and read the studies I cite in full to make an informed decision about what you are about to read. After all, I can be mistaken. This will be a point-by-point comment and refutation, as well as a discussing related topics in psychology and medicine. Let’s get started.
1. Causes of Depression
Prof. Coyne appear to argue, both in the entry itself and in the comments that the mainstream view of the causes of depression is primarily “chemical imbalance” in the brain. He even offers the anecdotal evidence that he has seen this stated in SSRI pamphlets and that several of his friends has been told this. This is really ironic because Prof. Coyne knows that anecdotes such as this does not make science and he even points this out in a later revision of the blog entry itself when he correctly points out that personal testimony that a medication has helped a person is not the same as a solid result from a scientific study with a solid methodology.
However, the mainstream view is not that the cause of depression is primarily a chemical imbalance in the brain. It never was, although it is true that it was a popular position in the past and lingers in the public perception of depression, kind of like how you sometimes read in popular works that evolution happens for “the good of the species”, despite the fact that Wynne-Edwards’ naive group selection is no longer taken seriously by most evolutionary researchers. Modern psychology is dominated by thinking about behavior in terms of different levels of analysis (e. g. evolution, psychology, environment), hierarchical reductionism and the distinction between ultimate and proximate causes. Let us see how this works with respect to depression (taken from Passer et. al 2009, a common university level textbook in psychology).
Biological factors affecting depression: genetic predisposition, chemical factors in the brain affected by antidepressants, perhaps an exaggerated form of adaptive withdrawal shaped by evolution etc.
Psychological factors affecting depression: negative thought patterns/distortions, pessimistic personality style, susceptibility to loss and rejection, perhaps linked to early life experiences etc.
Environmental factors affecting depression: previous life experiences of loss and rejection, current decrease in pleasurable experiences, increased life stress, loss of social support, cultural factors etc.
This factors can all affect the likelihood of developing depression and can interact with each other in complex ways. From this, it is easy to see how the strawman of “depression is said to be caused by chemical imbalance” skews the situation against science-based psychiatry from the very start, reminiscent to how creationists misrepresents evolution by saying that the proponents of evolution thinks that evolution proceeds by randomness and then and then smugly asks how produce complex structures such as the vertebrate eye can just randomly assemble. It can’t and that is the point. Complex adaptations are not assembled randomly in one fell swoop, but from many different, both random and non-random processes, such as mutation, natural selection, gene duplication, exon shuffle, alternative splicing etc. over large periods of time. Similarly, no sane researcher in psychology or psychiatry believes that depression is caused by a one-size-fits all cause and so the treatments are not believed to be “just drugs”, but can be others like psychotherapy, lifestyle changes and these can be successfully combined for even better effect, but more on this in later sections of this entry.
2. Is effectiveness of a drug not evidence for an underlying model?
Prof. Coyne writes that
Because these drugs seemed to work (more on that below), doctors and pharmaceutical companies blithely concluded that depression resulted from a deficit of serotonin. But that’s ludicrous, for just because a drug alleviates a symptom doesn’t allow you to conclude that the symptom was due to the deficit of that drug. It’s like saying that headaches are caused by a deficit of aspirin!
If a model about some condition or other predicts that a certain medication will treat the condition or alleviate the symptoms, and this in fact occurs, then this is evidence for said model because it is a pretty risky prediction that has been supported by the experimental data. Prof. Coyne might retort that it is not that good evidence, because perhaps the drugs have other effects which in turn are responsible for the improvement. Of course, nothing in science can be proven like a mathematical theorem can be proved, but when many different lines of evidence all converge on the same general conclusion, then we can give our provisional acceptance of this conclusion. To take a related example, the fact that ARVs work against HIV/AIDS progression is evidence for the causal model that HIV causes AIDS, because such a model predicts that ARVs inhibits the life cycle of the retrovirus.
3. Commence the anecdotes!
Prof. Coyne writes that
An acquaintance of mine, visiting a psychiatrist for depression, was told that her “brain was wired up wrong”! That verges on medical malpractice.
This is clearly a personal anecdote and Prof. Coyne knows it. If a supporter of alternative medicine made a similar anecdote Prof. Coyne would be the first to rip it to shreds. Does this acquaintance have a name? What psychiatrist did he or she visit? Is this representative for psychiatrists in general? Did the acquaintance quote the psychiatrist directly or just paraphrase? Is it possible that this acquaintance misunderstood what the psychiatrist where saying? It is very difficult to explain complex science to lay persons. Is it possible this was the psychiatrist way of saying that the acquaintance probably had a genetic predisposition to depression? Or did he tell the acquaintance that genetic predisposition is a contributing factor in some cases of depression? These are all very important questions that needs to be answered if anecdotes like this is suppose to be taken seriously.
4. Genetic Mapping vs. Estimates of Heritability
Prof. Coyne writes next that:
I also learned that the genetics of mental illness is a subject rife with uncertainty and unreproduceable results. For every study localizing a “gene” or gene region responsible for a condition like depression, there was a counter-study showing no effect at all. Nevertheless, medical students in psychiatry are taught that the major mental illnesses have a genetic basis (I’ve seen the textbooks).
It was about here I started thinking that Prof. Coyne’s blog entry surely must have been a parody because there is no way a practicing biologist who himself has done research in genetics could make this basic mistake. He confuses two different notions that is very important to keep separate: identifying a specific gene or gene region that predispose someone to depression and estimates of the heritability of depression. The latter is done by, among other things, twin studies and generally conclude with a number between 0 and 1, which is an estimate of the extent to which variation in phenotype in a population can be attributed to variations in genotype.
This means that it is entirely reasonable to state that many psychological disorders have a genetic predisposition if heritability studies show this, even though the research programs to find specific genes or gene regions may be “rife with uncertainty and unreproducible results”. There is a difference between knowing that and knowing how. Compare this with evolutionary biology: even though we do not have all the details of how common descent happened (is this taxon more related to that taxon than this other taxon?), we can be pretty sure of the fact of common descent. As I am sure that Prof. Coyne knows, confusing these two is a favorite past-time of creationists.
5. Oh noes! Conspiracies!
Prof. Coyne continues, arguing that
Despite all this, psychiatry continues to be increasingly “medicalized,” that is, talk therapy is replaced by drug therapy (doctors can make a lot more money prescribing drugs than talking, for during the hour occupied by a talk therapy session, a psychiatrist could see and prescribe meds to three or four patients). And pharmaceutical companies make millions of dollars prescribing drugs for mental illnesses, so they continually try to expand the range of conditions that count as drug-requiring “illnesses,” including obsessive-compulsive disorder, various attention-deficit syndromes, and so on.
This is a classic fallacy among pseudoscientists (appeal to motive), claiming that the science is wrong because practitioners and pharmaceutical companies are making money. Examples of this fallacy is claiming that someone who accepts evolution is only doing so because he hates the biblical god or do not want to be held accountable. There is absolutely no way that Prof. Coyne would have taken such a claim seriously. Furthermore, the exact same argument is put forward by the anti-vaccine movement against vaccines and by HIV/AIDS denialists against ARVs. Again, there is no way that Prof. Coyne could take those arguments seriously, yet when it comes to psychiatry, he seemingly cannot stop himself from peddling the exact same nonsense that he probably vigorously objects to in order areas.
To be sure, pharmaceutical companies have done unethical and dangerous things and there is a reason why regulation exists, but the bottom line is that even if large pharmaceutical companies only cared about making profits, it does not logically follow that their products are dangerous. In fact, an excellent way of making profit in the long run is by making good products that work. I suspect that Prof. Coyne has let his own political ideology corrupt his thinking on this issue. This is not to say that lefty liberalism is somehow wrong, just that it is possible for democrats as well as republicans to come to unwise conclusions from ideological concerns.
6. The DSM under attack!
Next on the list of targets is the Diagnostics and STatistical Manual of Mental Disorders. Prof. Coyne writes that
The whole mess is encapsulated in the book used by doctors to “diagnose” mental illnesses, the Diagnostic and Statistical Manual of Mental Disorders (DSM), which is now undergoing its fifth revision. If you ever get a chance to look at it, do. You’ll find that “diagnosis” is based on conforming to a certain number of symptoms in a numbered list. To be diagnosed with a “major depressive episode,” for example, you need to have five out of the nine symptoms described by the DSM. But what if you have only three or four? Then you don’t get your meds. It’s all quite bizarre, and I concluded that the whole drug/genetics/diagnosis nexus is driven by three things: the desire of psychiatrists to be like “regular” doctors who treat well defined illnesses with well defined medications, the nebulous and ill-defined character of mental illnesses, and the desire of pharmaceutical companies to milk the public out of as many dollars as possible. This does not deny, of course, that mental disorders are often serious and life-threatening conditions that require some type of treatment or intervention.
Actually, psychiatrists are “regular” doctors, trained in diagnostics; most of the time they have an M. D.
So the argument here is that diagnoses of mental illnesses are suspicious because they are based on symptoms rather than laboratory testing. It is true that there is no blood test for schizophrenia, but there are well-established diagnosis such as migraine that cannot be verified with clinical testing either. Does this undermine migraine as a diagnosis? Not in the slightest. Mental disorders are complex issues and there is possible that there will never be a diagnosis that correctly identifies everyone that suffers from the disorder and never indefiniteness individuals not suffering from the illness. So the best we can do (and this probably applies to many medical conditions outside mental health as well, such as HIV/AIDS), is to devise tests and criteria that maximizes the number of true positives, while keeping false positives and false negatives as low as we can. Now, if our criteria are too strict, then we will get a lot of false negatives (people that do have the condition fails to be diagnosed with it), but if our criteria are too lenient, we will get a lot of false positives (people who do not have the condition is diagnosed with it). The solution to the problem is not to throw out the DSM, but make it better.
It is also interesting to see that this line of argument also mirrors HIV/AIDS denialists, who argue that one criteria for being diagnosed as HIV seropositive (CD4 count less than 200) is arbitrary. However, while it is true that if we change it to 201, not a lot will change, making the criteria less than 50 has the potential of missing a lot of individuals with HIV/AIDS.
7. Efficacy of Antidepressants?
Prof. Coyne makes the disturbing claim that
Antidepressants are far less effective than people think: in fact, they may not be effective at all. […] More disturbing is that the drugs are barely better than placebos. Pharmaceutical companies doing blind testing of antidepressants are required to submit only two blind clinical studies with positive results, and these could be out of a much larger number of studies showing no positive results. That, in fact, seems to be the case. […] Moreover, when you look at the degree of improvement of antidepressants over placebos, the difference, though statistically significant, is miniscule. Few people taking antidepressants know these depressing statistics.
There are literally hundreds or even thousands of studies on antidepressants such as SSRIs and other antidepressants that show they are effective compared with placebos. One such example was recently published in NEJM (Walkup et. al. 2008), that compared the efficacy of sertraline (an SSRI) alone, cognitive behavioral therapy (CBT) alone, placebo, and Sertraline and CBT together and the results are fairly typical: improvement with CBT alone (59.7%), sertraine alone (54.9%) where both better than placebo (23.7%) and a combination of CBT and sertraine (80.7%) was the best option. Side effects where roughly equal in the group recieving the SSRIS treatment and the group receiving placebo. This study is not perfect, but it independently converges with other such studies showing that SSRIs are by and large effective compared with placebo.
So what is going on here? As there are hundreds and hundreds of studies on efficacy of SSRIs, it is useful to collect these and combine them into one analysis. However, meta-analysis has several limitations and biases because the authors themselves decide what studies to be used. If you only investigate papers that have desired outcomes or using arbitrary restricting inclusion criteria, you have the seed to a very bad meta-analysis and this is probably what has occurred here. Prof. Coyne has unfortunately been bamboozled by a couple of poorly executed meta-analyses.
On the blog Science-Based Medicine, Amy Tuteur dissects the Fournier (2010) in her post Study shows antidepressants useless for mild to moderate depression? Not exactly.
- The study only selected 6 studies out of hundereds and of these 6 only 3 used an SSRI drug (Paxil). The other three used a tricyclic antidepressant (imipramine) that has not been the standard for over a decade due to side effects.
- All SSRIs have the same mechanism of action, but different efficacy and side effects, so conclusions from Paxil cannot haphazardly be extrapolated to all SSRIs
- The study used some arbitrary inclusion criteria such as availability of patient level data. As most RCTs do not include patient level data, this criterion excludes most studies.
- The initial analysis identified 23 studies, but as the researchers could only gain access to the data in 6 studies, so they just ignored the other 17.
All of this, taken together, means that this study cannot be used to argue against the efficacy of SSRIs in the way that opponents of medical psychiatry hopes it can be. It is very likely that other meta-analyses of this kind purporting to show the ineffectiveness of SSRIs compared with placebo has similar problems.
8. Side Effects and Blatant Contradiction Goes Unnoticed
Prof. Coyne claims that
Whitaker concludes that psychoactive drugs actually change the brain in a way that prolongs and intensifies mental disorders, for the brain tries to compensate, ineffectually, for the chemical imbalances induced by drugs.
This is a quite bizzare claim, because was it not just recently that Prof. Coyne claimed that mental illnesses are not caused by chemical imbalances? And now he claims that mental disorders in general are caused by chemical imbalances? He cannot have the cake and eat it took. Prof. Coyne then goes on to quote Whitaker’s fallacy of misleading vividness about the side effects of anti-psychotic medicine. Yes, anti-psychotic medication, like all medication, has side effects (although not all side effects are very common). The acceptability of side effects depends on what the condition being treated is. For instance, relatively few side effects are tolerated when it comes to medication against high blood pressure, but relatively many and severe side effects can be tolerated if it is a successful treatment against cancer that is usually terminal. Would you rather have diabetes or have psychotic breaks?
9. Seriously? Autism? You have got to be kidding me!
This was another part of Prof. Coyne’s entry that made me think it was a joke: discussions of the increased prevalence of autism in relation to drug therapy. He writes that:
Perhaps the most disturbing thing in Angell’s articles is the huge increase in drug therapy for mental disorders in children, who are often treated with drugs not approved by the FDA for their diagnosed disorder. “Juvenile bipolar disorder” increased 40-fold between 1993 and 2004, and autism more than fivefold. As Angell notes, “Ten percent of ten-year-old boys now take daily stimulants for ADHD—’attention deficit/hyperactivity disorder’—and 500,000 children take antipsychotic drugs.”
As most of us know, the anti-vaccine movement likes to claim that there has been a sudden increase in diagnosis of autism and that this is caused by pharmaceutical products such as vaccines. This is wrong, because we are pretty sure that changes in diagnostic criteria and increased awareness and there is no association between vaccines and autism. There is no general effective pharmaceutical treatment for autism (although there is a large market for ineffective alternative treatments that i doubt major pharmaceutical companies peddle), but CBT (a talking therapy) has shown some minor promise. So why does Angell mention autism at all? Why does Prof. Coyne repeat it at the same time that he claims that talk therapy is increasingly being replaced by medication when the science shows that combinations of medications and CBT are better and that certain conditions like autism can only be treated with CBT at the moment, if that? Many important questions that needs to be answered.
10. Prof. Coyne finally goes of the deep end
In the final passages of his blog entry, Prof. Coyne makes a startling series claim:
These articles, and the data presented by Angell, have convinced me more than ever that medical psychiatry is largely a scam, a rotten-to-the-core coalition between psychiatrists and pharmaceutical companies. Now I know that many psychiatrists are deeply motivated to help their patients, for mental disorders are among the most frustrating and recalcitrant conditions faced by doctors, and many patients indeed need urgent medical or therapeutic attention. But the way it’s being done now is not only ineffective, but positively harmful—although lucrative for doctors and drug companies. The few researchers and psychiatrists crying out against the madness, as in the three books under review, are largely shouting in the wilderness.
Let us together count the warning signs of pseudoscience here: (1) has been convinced by a book review that an entire field of science is a scam, (2) admits in the comments that he has not read the studies himself, (3) postulates a grand Big Pharma conspiracy, (4) claim that well-tested medication is not only ineffective but harmful, (4) claim that medicine designed to prevent something causes it (5) appeals to a small minority of people and insinuating that they are suppressed by the establishment. This is classic debate tactics we all know and accept is indicative of pseudoscience. We would never ever buy it if it was peddles by a creationist, an anti-vaccine supporter, an HIV/AIDS denialist etc. Let us hold Prof. Coyne to the same standards.
11. The Responsibility for Spreading Pseudoscience
The former South American President Thabo Mbeki was an HIV/AIDS denialist who believed that ARVs where created by by the west to destroy the future of Africans, so he blocked the populations access to them. According to researchers at Harvard School of Public Health, his actions lead to the premature death of over 340000 people.
Now, the result of Prof. Coyne peddling anti-psychiatry nonsense is most likely not that bad, but he must realize that his actions does not occur in a vacuum. Who knows how many patients with severe depression read his entry, went off their medications (why take medications if they are ineffective and merely have horrible side effects?) and killed themselves. He will always have the blood of these people on his hands. To be sure, they might have been that unstable that they would have gone of their medications from reading about it somewhere else or hearing a friend talk about it, but it is worth contemplating nonetheless. Prof. Coyne added a ambivalent disclaimer after a while urging patients who did take medications to not stop taking them, but read the book reviews anyways. This is kind of like urging someone not to take their life, but handing them a loaded gun and asking them to try it out for a while.
Stop trusting everything you read in the newspapers about science. Remember the New Scientist “Darwin was Wrong” debacle? Remember Cardinal Christoph Schönburn’s NYT op-end “Finding Design in Nature”?
It is intellectually irresponsible and morally reprehensible.
12. References and Further Reading
Hall, Harriet, (2009). Psychiatry-Bashing. Science-Based Medicine. http://www.sciencebasedmedicine.org/index.php/psychiatry-bashing/. Accessed 2010-06-26
Tuteur, Amy Tuteur. (2010). Study shows antidepressants useless for mild to moderate depression? Not exactly.. Science-Based Medicine. http://www.sciencebasedmedicine.org/index.php/study-shows-antidepressants-useless-for-mild-to-moderate-depression-not-exactly/. Accessed 2010-06-26
Walkup, J. T., Albano, A. M., Piacentini, J., Birmaher, B., Compton, S. N., Sherrill, J. T., . . . Kendall, P. C. (2008). Cognitive Behavioral Therapy, Sertraline, or a Combination in Childhood Anxiety. New England Journal of Medicine, 359(26), 2753-2766. doi: doi:10.1056/NEJMoa0804633
Passer, M., Smith, R., Holt, N., Bremner, A., Sutherland, E., & Vliek, M. (2009). Psychology: The Science of Mind and Behavior. New York: McGraw-Hill Education.
Offit, P. A. (2008). Autism’s False Prophets: Bad Science, Risky Medicine, and The Search For a Cure. New York: Columbia University Press.
Kalichman, S. (2009). Denying AIDS: Conspiracy Theories, Pseudoscience, and Human Tragedy. New York: Copernicus Books.
Chigwedere P, Seage GR, Gruskin S, Lee TH, Essex M (2008). “Estimating the Lost Benefits of Antiretroviral Drug Use in South Africa“. Journal of acquired immune deficiency syndromes (1999) 49 (4): 410–415.