"Brain Chemical Imbalance" Theory Is Fading Out as an Explanation for Mental Illness

An interesting exercise is to try the following Google query:

What causes mental illness?

Let us look at the extremely diverse results that come up on the first  page of search results that appear when we do such a Google query. Strangely, the first result is an article that does not make any attempt at all to suggest any explanation for a cause of mental illness. The second search result is a page from a small organization that states this:

"Most psychiatric survivors reject the term 'mental illness' altogether, as it supports what is considered the 'medical model' of mental health. The medical model is based on the idea that there is a physiological impairment creating a neurochemical imbalance in a person’s brain, resulting in a mental illness. Despite this popular perspective, it is based on flawed science."

The third result is a page that does not make any attempt at all to suggest any explanation for a cause of mental illness. The fourth result is a page that attempts to explain mental illness by first mentioning genetics. The page suggest that there might one day be some kind of genetic or epigenetic way of reducing suicide.  The page suggests that "macrophages" and "inflammation" somehow contribute to mental illness. 

The fifth search result is a page from a leading medical clinic, the Mayo Clinic. In a section entitled "Causes," the page lists three causes for mental illness:  "Inherited traits," "Environmental exposures before birth," and "Brain chemistry." What the page suggests under "brain chemistry" is basically the same idea that is rejected by the second search result (on this page). 

(I may note that after years in which the medical community kept telling us that mental illness is caused by imbalances of brain chemicals, we now have many authorities who are denying such claims. Such authorities sometimes claim that the medical establishment never taught that mental illness is caused by imbalances of brain chemicals. But the doctrine of mental illness being caused by brain chemical imbalances still is taught very widely by many medical authorities, and evidence of the massive teaching of the doctrine by the medical and neuroscience establishment can effortlessly be found very abundantly by searching for the past statements of such authorities.) 

The sixth search result is a page entitled "What causes mental illness?" The answers suggested (from first to last) are genetics, environment, childhood trauma, stressful events, negative thoughts, unhealthy habits, drugs and alchohol, and brain chemistry. The page tells us this: "Mental illness involves an imbalance of natural chemicals in your brain and your body."  This is the "chemical imbalance" theory of mental illness that numerous authorities are now saying is not true, and which some authorities are claiming was never taught. It very obviously was taught and continues to be taught by leading authorities. 

The seventh search result is a page from the widely read WebMD site. The page suggests the "chemical imbalance" theory of mental illness, along with a widely spread "bad wiring" theory. The page also suggests causes of genetics, infections, brain defects or injury, and substance abuse.  The page also mentions "stressor" events such as death or divorce, changing jobs, feelings of inadequacy and a dysfunctional family life.  The page kind of goes "all over the map" in trying to explain the causes of mental illness. 

The eighth search result is a 2012 page on the site of the American Psychological Association, one entitled "The Roots of Mental Illness." At first the page starts out by pitching purely biological causes of mental illness. We read this:

"Eric Kandel, MD, a Nobel Prize laureate and professor of brain science at Columbia University, believes it's all about biology. 'All mental processes are brain processes, and therefore all disorders of mental functioning are biological diseases,' he says. 'The brain is the organ of the mind. Where else could [mental illness] be if not in the brain?' "

We certainly do not know that all or even most mental processes are brain processes, and there are very strong reasons (discussed on this blog) for rejecting claims that all or most mental processes are brain processes, a claim which is dogma, not fact. As for the "where else" reasoning of Kandel, it is a type of rhetorical question sophistry that can sound convincing only because of the lack of imagination in the person hearing it.  The same type of fallacious reasoning was long used about DNA. People would say that DNA must contain some blueprint for making a human, arguing, "Where else could such a blueprint be?" The fact is no such blueprint has ever been discovered in DNA, which contains only low-level chemical information, not high-level structural information.  We can reasonably answer Kandel's question like this: mental illness (along with most other mental phenomena such as memory) could be in some non-material reality of a human (such as a soul) that is something different from the brain. 

Next on the 2012 "Roots of Mental Illness" page of the American Psychological Society, we read this: "That viewpoint is quickly gaining supporters, thanks in part to Thomas R. Insel, MD, director of the National Institute of Mental Health, who has championed a biological perspective during his tenure at the agency."  But a mental health expert claimed in a recent interview that Insel's "13 years in charge of the nation’s mental health research produced such uniformly dismal results."  The expert stated this, quoting Insel:

"When Insel stepped down as director of NIMH in 2015 he gave an interview about his accomplishments, after spending by his estimate $20 billion. 'I spent 13 years at NIMH really pushing on the neuroscience and genetics of mental disorders, and when I look back on that … I don’t think we moved the needle in reducing suicide, reducing hospitalizations, improving recovery for the tens of millions of people who have mental illness.' ”

Indeed, in its second part the 2012 "Roots of Mental Illness" page of the American Psychological Society shifts gears, giving us this quote:

"That complexity is one reason that experts such as Jerome Wakefield, PhD, DSW, a professor of social work and psychiatry at New York University, believe that too much emphasis is being placed on the biology of mental illness at this point in our understanding of the brain. Decades of effort to understand the biology of mental disorders have uncovered clues, but those clues haven't translated to improvements in diagnosis or treatment, he believes. 'We've thrown tens of billions of dollars into trying to identify biomarkers and biological substrates for mental disorders,' Wakefield says. 'The fact is we've gotten very little out of all of that.' "

The ninth search result gives another "all over the map" smorgasbord of reasons for mental illness. In a similar vein, the tenth search result is a page of the Center for Disease Control. Under a heading of "What Causes Mental Illness?" we read the following:

"There is no single cause for mental illness. A number of factors can contribute to risk for mental illness, such as

• Early adverse life experiences, such as trauma or a history of abuse (for example, child abuse, sexual assault, witnessing violence, etc.)
• Experiences related to other ongoing (chronic) medical conditions, such as cancer or diabetes
• Biological factors or chemical imbalances in the brain
• Use of alcohol or drugs
• Having feelings of loneliness or isolation"

The eleventh search result is a page that offers an extremely wide range of things that can affect mental health:

"

• childhood abuse, trauma, or neglect
• social isolation or loneliness
• experiencing discrimination and stigma, including racism
• social disadvantage, poverty or debt
• bereavement (losing someone close to you)
• severe or long-term stress
• having a long-term physical health condition
• unemployment or losing your job
• homelessness or poor housing
• being a long-term carer for someone
• drug and alcohol misuse
• domestic violence, bullying or other abuse as an adult
• significant trauma as an adult, such as military combat, being involved in a serious incident in which you feared for your life, or being the victim of a violent crime
• physical causes – for example, a head injury or a neurological condition such as epilepsy can have an impact on your behaviour and mood. (It's important to rule out potential physical causes before seeking further treatment for a mental health problem)."

The page rejects the "brain chemistry imbalance" so often advanced around the turn of the century, stating the following:

"The human brain is extremely complicated. Some research suggests that mental health problems may be linked to a variation in certain brain chemicals (such as serotonin and dopamine), but no one really understands how or why. Arguments that someone's brain chemistry is the cause of mental health problems are very weak. But even though there's no strong evidence to say that any mental health problems are caused by a chemical imbalance in our brains, you might find some people still use brain chemistry to explain them."

The 12th search result also suggests a wide range of causes for mental illness. The 13th search result is a World Health Organization page that does not attempt to describe the causes of mental illness. The 14th search result is a National Institute of Mental Health page that also does not attempt to describe the causes of mental illness.

From these results it seems we can draw three conclusions:

(1) The claim that mental illness is caused by brain chemical imbalances is a claim that is still being pushed here and there by various authorities.

(2) Such a claim is now disputed by many other authorities on mental illness, who say that there is no robust evidence for such a claim that mental illness is caused by chemical imbalances in the brain.

(3) The most common answer given regarding the cause of mental illness is a multi-factor answer that mentions a wide variety of possible causes, many of which include things other than brain states.

There was never any good evidence for the theory that mental illnesses are caused by brain chemical imbalances. The theory was popular largely because it was pushed by pharmaceutical companies. Neuroscientists often sounded supportive of the theory partially because many of them are financially entangled with  pharmaceutical companies.

A recent article on the Psychology Today web site is an illuminating expose of how doctors, professors and pharmaceutical companies long pushed an unwarranted theory that depression is caused by a chemical imbalance, an imbalance of the chemical serotonin. The article tells us that the theory was so widely spread by authorities that more than 80% of the public believed it, according to polls. We read this:

"A major new review of the research—the first of its kind exhaustively reviewing the evidence, published today in the journal Molecular Psychiatry—reaches a strikingly similar conclusion. In 'The Serotonin Theory of Depression: A Systematic Umbrella Review of the Evidence,' University College London Psychiatry Professor Joanna Moncrieff and a team of five other top European researchers found 'there is no evidence of a connection between reduced serotonin levels or activity and depression.' ...The researchers also looked at studies where serotonin levels had been 'artificially lowered in hundreds of people' (by depriving their diets of the necessary amino acid that makes serotonin) and found that 'lowering serotonin in this way did not produce depression in hundreds of healthy volunteers,' according to a 2007 meta-analysis and several recent studies. Numerous other reviews on re-examination were found to provide weak, inconsistent, or nonexistent evidence of a connection between serotonin and depression."

It was the same thing going on in regard to the serotonin theory of depression and the theory that the brain is the source of the human mind and the storage place of memories:

• In both cases a community of experts became a belief community with the goal of propagating some dubious explanation.
• In both cases an overconfident community of experts "jumped the gun" by claiming to understand things beyond its understanding. 
• In both cases the community of experts developed speech customs that were not based on sound scientific evidence, and were contrary to many observations.
• In both cases the story line being told served the vested interests of the experts, by helping to make them look like great lords of explanation who understood deep mysteries of the mind. 

Just as our professors and psychiatrists misled us for so long with unfounded theories of mental illness being caused by chemical imbalances, professors and psychiatrists and neuroscientists have misled us for so long by advancing unfounded claims that human minds comes from brains and that brains are the storage place of memories. The social construction of the serotonin theory of depression is a sociology story very similar to the sociology story of the social construction of claims that brains make minds and store memories. To understand how and why such folklore began to be told, use a rule of "follow the money" and ask this again and again: "Who was it benefited by the telling of such stories, and in what ways did they benefit?" And also ask again and again: "In what ways did the tellers of such stories break the rules of proper scientific inquiry, in a way that led to their own benefit?"

When the oppressed are sad largely because they have been oppressed, it is very convenient to tell such people that they are sad because of some problem in their brain that can be fixed if they buy pills, rather than because of all of the things that society has done to oppress them. Part of this oppression comes from academia itself, but explaining how that works would require a separate post.

And speaking of errors about brains, today's Health page on Google News has a link to an article entitled "Two decades of Alzheimer's research may be based on deliberate fraud that has cost millions of lives."

Postscript: The post here documents how leading authorities long pushed the serotonin theory of depression, and how some of them are backtracking, changing their web sites and claiming they never really believed such a thing (often in contrast to their previous statements).  At this page we read of a psychiatry professor who has been trying to stop using "anti-depression" SSRIs, through a very gradual reduction lasting years. We get the impression of some great hazard in suddenly stopping their use. But in the TV shows we never hear a psychiatrist say, "I'm going to put you on this pill, but it's pretty addictive." Claims that the serotonin theory of depression was a mere "urban legend" not taught by psychiatrists and neuroscientists are debunked in a scientific paper entitled "Is the chemical imbalance an ‘urban legend’? An exploration of the status of the serotonin theory of depression in the scientific literature." That paper documents that very many psychiatrists and neuroscientists taught such a theory for decades, before beginning to backtrack around 2022.