On The Validity of Brain Scans as Proofs of Psychiatric Theories

by Dean Blehert

Dr. Grace Jackson, a psychiatrist and an expert on brain imaging, refutes the validity of the attempts by various psychiatrists to defend the "science" of their diagnoses by using comparative brain scans. Her article, which, I've linked below my own write-up, along with her references, is technical enough to leave many readers in the dark, so I've tried to put her main points into simple, non-technical language first, then link the article for those who want all the technical details. This way the data may be more usefully forwarded to others. Dr. Jackson doesn't go into the most basic lies in psychiatry's science, but since many may be impressed when a psychiatrist on TV holds up brain scans, it's useful to know a bit about the science and NON-science behind these scans. Here's my understanding of Dr. Jackson's points:

Psychiatrists are attempting to refute the assertion that there's no real science behind psychiatry. The chief criticism is that psychiatry defines sets of symptoms as diseases caused by chemical imbalances in the brain (especially, lacks of certain neuro-transmitter chemicals) -- and does so with no evidence that any such chemical imbalances exist. Psychiatrists reply by holding up photos of brain scans. One photo will be (allegedly) a scan of the brain of someone with a psychiatric "illness", for example, ADHD; the other scan will be that of someone (allegedly) normal. The psychiatrists say, look at the pattern of neural activity in the "ADHD" brain, and note how it's not like the pattern of activity in the "normal" brain. When the ADHD person is given an anti-ADHD drug (like Ritalin), then it looks like the normal brain. And that's been the basis for psychiatric classification of illnesses, all very scientific.

[Note: Of course, the last sentence above is simply a lie: The illnesses were created by vote long before the brain scans were developed to justify the vote.]

This use of brain scans to prove the existence of mental illness is bogus for several reasons:

1. The people who show these brain scans to the press don't differentiate between the two broad categories of brain scans, Anatomical and Functional. The anatomical scans are reliable, well-established techniques, in use for over 50 years. The functional scans are still relatively controversial research tools.

The anatomical scans give us a view of the brain, not in action, but static. They don't show activity well. They do show tumors, brain damage and other relatively unchanging phenomena. They don't show things like firing of nerves or flow of blood. No one has yet been able to use Anatomical scans to demonstrate any correlation between the various mental illnesses named by psychiatrists and the phenomena (tumors, damaged tissue, etc.) that show up in Anatomical scans. So the most reliable scans do NOT demonstrate the validity of psychiatry, do NOT show correlation between the brain phenomena they reveal and psychiatric illness.

2. The Functional scans attempt to show us brain ACTIVITY when the person is at rest or engaged in some specific activity. The recent assertions of psychiatrists (in defending psychiatry) have been that the functional scans show the brain's activity (its nerves firing, etc.). Actually, the functional scans show the flow of blood within the brain. This flow of blood does NOT necessarily indicate an area of nerve activity. That is, a functional scan that shows activity on, say, the right side of the brain does not show "brain" activity on the right side of the brain, where, by "brain" activity, is meant the firing of neurons, the transmission of impulses from neuron to neuron via neuro-transmitter chemicals, etc. It shows a flow of blood to that part of the brain. Various studies have shown that the flow of blood to a part of the brain does not necessarily correlate with neuro-activity in that part of the brain. In fact, some studies suggest that the blood flows to INactive parts of the brain to get them more active. Other studies suggest that signs of activity in one part of the brain are actually caused by nerve activity in another part of the brain.

There are all sorts of variables involved, and the research on this area is far from conclusive. When a scan shows increase in circulation to a part of the brain, we don't know what it shows in terms of "brain activity."

3. Claimed comparisons of functional scans of so-called diseased brains to those of so-called normal brains have all been invalid, since they failed to take into consideration the various factors that influence brain circulation, including age, diet, gender, medical condition, weight, height, whether on drugs, drug history, education, etc. All of these and other factors influence the way a brain looks on a functional brain scan. (In one notorious study, the supposed differences between the normal and abnormal brains were entirely explained when it was learned that one of the groups was significantly older than the other. In another study, the people with alleged psychiatric illnesses showed brain abnormalities that were entirely explained when it was discovered that they were all on psychiatric drugs, and that the drugs were known to cause such abnormalities.)

4. The idea that a functional scan gives an instant view of brain activity is false. The sorts of brain activity we're interested in (neuro-activity) is instant, happening in thousandths of a second. A functional scan shows shifts in circulation, which, even where thought to be associated with brain activity, lag behind that activity by a few seconds (a few seconds being hundreds of times longer than the brain activity itself). In other words, this is a very crude view of the brain in action (if it is a view of brain activity, which is doubtful, since the relationship of shifts in blood circulation to brain activity are still not well understood).

5. The psychiatrists presenting these images to the public imply that we are looking at images of two brains, one normal, the other diseased. In fact, each image is a statistical average of many images. No one individual has either of these scans, and the averaging suggests clearer and more consistent differences that would not show up in individual scans. Individual scans (even assuming all the earlier points were handled) have far too much variability to be reliable for diagnosis. Where imaging studies compare groups of "normal" and "abnormal" brains, there is a large overlap between the groups. Many people alleged to be ADHD, for example, do not show the brain patterns claimed to be characteristic of ADHD.

6. Assertions that image comparisons show that certain locations of the brain are the sources of various conditions are not scientific assertions, and make a number of invalid assumptions.

7. If these imaging techniques are to be used to make valid diagnoses (they can't, really — see above), then other problems come up: The imaging techniques themselves are possibly dangerous — dangers yet unknown, but they do disturb the brain.

Three other points not covered in the article referenced:

1. Such image comparisons depend on someone deciding that a person is normal or is ADHD (or schizophrenic or whatever). Who makes this decision and on what basis? Presumably one or more psychiatrists labels someone ADHD. Yet the criteria for this are vague enough and broad enough that they could be made to fit anyone. When a psychiatrist holds up two brain scans and says that scan A is that of an ADHD brain and scan B is that of a normal brain, who has decided (prior to the brain scans being made) that the first person is ADHD and the second is normal? Does psychiatry even have a definition of "normal"? How does one verify either of these assertions.

It is known (from various studies) that psychiatrists differ greatly in their diagnosis of individuals; that for any person on trial who claims insanity, psychiatrists can be found both to defend and attack that claim; that psychiatrists have often released people from institutions as "cured" or "no longer dangerous", who have then murdered; that psychiatrists, given people to diagnose who included students hired as experimental subjects or newspaper reporters or others who, to non-psychiatric eyes, appeared normal, have mis-diagnosed them as insane and ordered them committed.

All we know is that two images we are shown look different. The validity of calling one image normal, the other diseased, depends on how much we are willing to rely on psychiatric classification in the first place. In other words, it assumes what psychiatrists claim to be proving with the images. To prove something by first assuming the validity of what you are trying to prove invalidates your proof. In other words, if, in order to prove that all dogs are purple, I have to assume that all dogs are purple, I have no valid proof. Those who find psychiatry to be bad science show that the psychiatric label, ADHD, is based on no science, and is described so broadly that it is possible to apply the label to anyone. Psychiatrists then show that slides of the brains of "ADHD" people differ from slides of "normal" people. So psychiatrists are assuming what is to be proven: that they can validly label some people as ADHD.

2. Even if it were true that some known pattern of brain activity corresponded to some known uncomfortable mental state, that wouldn't prove that the brain activity caused the mental state or that the mental state should be handled by medicating the brain. Here's an example: Let's say that brain scans of sad (depressed) people show less activity in a certain part of the brain. So you medicate the guy and the activity in that part of the brain increases, and also, he feels less depressed. What's wrong with this? A bit more investigation shows that the guy got sad when his girlfriend left him. We look at guys who've been dumped by their girlfriends, and find that they usually get depressed, and their brains get this same pattern. Now, which is the cause that is most likely to respond to treatment? Helping the guys get over being dumped, helping them to handle the factors in their lives that make it hard for them to find stable girlfriends, etc., or drugging them to make their brains "normal"?

More investigation will probably show the following:

A. The drug solution is forever. After a while, the drug ceases to boost brain activity, so more of the drug is needed, and eventually other drugs are needed. If the person goes off the drug, his brain is no longer as capable of that activity. (Usually the body loses the ability to do what a drug has done for it.) So the activity in that part of the brain is lower than it was to start with if he withdraws. And if he stays on the drug and additional drugs to handle the eventual failure of the first drug, he develops all sorts of health problems (liver toxicity, etc.). All this in addition to the various "side effects" of the drugs.

B. Because he simply suppresses the sadness, he never does handle the reasons why his girlfriend dumped him (or he lost his job or whatever precipitated the depression). He's running away from life, not facing it, and, worse, losing the ability to face it.

The point is that showing a correlation between brain function and mental state is necessary, but not sufficient to show, scientifically, that the brain function is the cause of the mental state. Cause here means source -- or, if that's too metaphysical, it means that which, when handled, eliminates the difficulty. Liposuction gets rid of fat, just as drugs claim to get rid of supposedly bad brain patterns, but no one claims that liposuction handles the cause of being obese, nor is there evidence (that I know of) that indicates it improves health -- on the contrary.

C. Any alleged science that is developed after the fact to prove what has earlier been asserted without proof must be doubted. Psychiatrists asserted that hundreds of conditions were illnesses caused by chemical imbalances of the brain long before these brain-imaging techniques were used to attempt to justify those assertions. This is lousy science from the start, because the scientists are trying to justify old assertions, not to find out what is, in fact, the case. A good scientist tries to DISprove his hypothesis, not to prove it.

Reference:

A Curious Consensus: "Brain Scans Prove Disease"? By Grace E. Jackson, MD

http://psychrights.org/Articles/GEJacksonMDBrainScanCuriousConsensus.pdf

Right click here to download a copy of the article as PDF file.