Jackie, I don't know exactly what midazolam does to the human brain, but it has been shown to produce neuronal apoptosis in laboratory animals. And I, for one, do believe that it causes some level of neurological damage in humans. Perhaps the drug's potency causes damage to the GABAA receptor complex, similar to that seen in people who have taken benzodiazepines for years. But I think the larger issue is that science is still quite far from being able to definitively map individual cognitive functions to particular brain anatomy, with any real level of specificity. I think many researchers would like to think that they can do that, but contemporary understanding of the human brain remains (from my view, at least) in a stage of relative infancy. Given this circumstance, I think it's a huge mistake for the medical profession to make such frequent use of drugs that are purported to either disrupt or enhance specific brain chemistry. My point being, if one doesn't understand how a machine is supposed to work when it actually works properly, I think it's a bit naïve to disrupt the function of that machine and not at least consider the possibility that said disruption could damage the machine's parts. I mean, since you're not altogether sure of how the machine worked in the first place, exactly how can you be sure that the disrupting stimulus won't cause damage to it? And yet, many doctors and nurses continue to scoff at the idea that midazolam can cause brain damage.
I think that different people's brains emphasize different neurotransmission systems. That is, there is no "single" brain, obviously brain chemistry varies from person to person. Therein lies the problem with something like midazolam, I think. Since it (and any other drug, for that matter) is a fixed entity, I think it stands to reason that the drug will exert different effects on different people. This is because the "organ" on which the drug works is the central nervous system. By contrast, if fifty people were to each get a bad paper cut, and each of them poured some hydrogen peroxide onto a cotton ball and then pressed the cotton ball into his or her cut, I don't think there would be any enormous amount of variation among the physiological reactions caused by the peroxide entering into each person's cut. That type of drug mechanism is fairly easily quantifiable.
But when you start tinkering with one of the most delicate chemical environments in the universe (or, arguably, the most delicate chemical environment in the universe)—i.e., the human brain—you're asking for trouble. Contemporary medical science has, however, reached a level of arrogance so positively stratospheric, that it has deluded itself into thinking that certain drugs can actually work on higher cognitive functions with specificity. I personally think that this belief is delusional. The human brain (and its equally important relative, the human mind) are obviously not one-size-fits-all entities. And since they are not, medical science will typically point to the example of "most people" whenever a psychoactive drug appears to not work the way they expected it to. And who exactly are "most people"? Well, in 2009, "most people" seem to watch American Idol. In 2009, "most people" are lucky if they can compose a coherent sentence. In 2009, "most people" can't spell words consisting of more than three syllables.
My point is, it is hugely problematic to administer drugs that are known to affect higher cognitive functions, when there is no real "norm" for any cognitive function. This is the basic problem of contemporary psychiatry, as well. Psychiatry has shifted these days to an almost exclusively biopsychiatric model. The basic flaw of such a model is that it requires "normal" brain chemistry to be defined. And that is something that simply cannot be defined, because it is an arbitrary and subjective assessment. Whoever is given the power to make such an assessment is, at best, playing a guessing game. That cirucmstance would be bad enough on its own, and it's also way too much power for any entity other than God to be given. But when you combine that power with the power to synthesize and administer powerful brain-disabling drugs (as a so-called "remedy" for brain chemistry that has been arbitrarily deemed "not normal"), you've got a near-perfect recipe for patient abuse.
I also wonder—at what point do medical practitioners treat a given brain with respect, and not vandalize it with something like midazolam? For example, if Albert Einstein were alive today and needed an appendectomy, would he be given intravenous midazolam preoperatively? Or would doctors, who obviously know full well the problems associated with the drug, spare Einstein's brain? Who knows. Given how widespread midazolam's use currently is, the brains of "most people" evidently don't warrant that type of respect. There are, however, plenty of doctors and nurses out there who steadfastly refuse to be given midazolam themselves, or to allow their relatives to be administered the drug. But everyone else, I guess, is on his or her own.