A boy, his brain, and a decades-long medical controversy
There seems to be an assumption underlying medicine that things must be true at the population level for them to also be true at the individual level. I think medicine is picking its populations wrong. Example: the skeptical doctor in the article notes that &quot;strep infection is extremely common in children, accounting for as many as a third of all sore throats—but you don’t see droves of kids with abnormal behavior crowding emergency departments and psychiatric clinics in late winter and early spring.&quot; But what if a more complex chain of events, or a genetic or immunological abnormality, is necessary to go from strep -&gt; psychiatric episode? Meaning that there might be a very small sub-population of children for whom strep has a chance of causing these symptoms.<p>I also see this thinking erroneously applied to other psychiatric disorders like depression. Antidepressants seem to help some people, and not help some other people. Averaged over the entire population, they appear to have a mild positive effect. But there could easily be multiple causes of depressive symptoms, based on genetics, diet, behavior, drug use, and past trauma. Why do we take it as a given that antidepressants should help all of these sub-populations equally?<p>To take it to an extreme, there are many causes of blindness. Giving vitamin A to someone who lost his eyes in a car crash will clearly not help, even though vitamin A can &quot;cure&quot; blindness in some people. If we ran a double blind trial of vitamin A as a cure for blindness, it would almost certainly fail at the population level because blindness caused by vitamin A deficiency is a very small sub-population of all blind people.