The chemical imbalance theory highlights a tendency in Western medicine to adopt a reductionist approach, where conditions are often attributed to a single cause and treated with a singular solution, typically a pharmaceutical agent. This mirrors the adage that to a man with a hammer, all problems look like nails.
Cholesterol was seen as the main cause of heart disease and millions were treated with cholesterol lowering medication. Subsequently, it became apparent that simply lowering cholesterol in the bloodstream and seeing a lower number on a pathology result was not translating into lower rates of heart disease.
The least understood part of the human being is the brain and nervous system. We know much more than decades ago but still know very little. The tendency to look for a single cause of mental health illness has led to the theory that low serotonin levels are the cause of depression. This was embraced by the pharmaceutical industry, the medical profession, and the public as a logical reason which offered a logical solution – a pill.
Prozac was the first selective serotonin reuptake inhibitor (SSRI), which was thought to work by enabling more serotonin to remain in the “connections” between nerve cells. In 2009, psychologist Irving Kirsch published a book called “The Emperor’s New Drugs,” challenging this theory.
By this time, it had come out that trials of SSRI medications had been selectively published. Those showing a benefit over placebo were published, and those that did not show an appositive effect were not. Initially, published data had shown medications to be significantly better than placebo. When all data (published and unpublished) were examined, it was found that in mild and moderate depression, SSRI medication was no more effective than placebo.
In other words, people got better because they believed the pill would help rather than because of a direct action of the pill. A reminder of the power of the mind.
In July results of an “exhaustive” UK review of the research concluded that there is no basis for the belief that low serotonin levels are the cause of depression.
“We found no consistent evidence in the main avenues of serotonin research that there is an association between serotonin and depression, and we found no support for the hypothesis that lower serotonin activity or concentrations are responsible for depression,” senior author Mark Horowitz, GDPsych, MBBS (Hons), PhD, of the Division of Psychiatry, University College London, UK, told Medscape Medical News.
“It’s not an evidence-based statement to say that depression is caused by low serotonin; if we were more honest and transparent with patients, we should tell them that an antidepressant might have some use in numbing their symptoms, but it’s extremely unlikely that it will be the solution or cure for their problem,” he said.
This is a significant finding and, in my opinion, should be widely reported in both the medical and mainstream media. This is unlikely to occur, and you can form your own views as to why.
SSRI medications still have a role but like many medical treatments, we see mission creep. The number of prescriptions issued in the USA and Australia, to name but two, suggests very strongly that they are likely being used where the benefit is questionable at best.
Medscape notes surveys show over 80% of the public believes the serotonin theory which was widely publicized in the 1990s with the introduction of SSRIs. The theory was only one of many developed in the 1960’s.
“Most people think that depression is caused by a ‘chemical imbalance’ in their brains or by low serotonin, and this is what many doctors tell patients who are depressed,” Horowitz said. “It has been known in academic circles that no good evidence has ever been found of low serotonin in depression, but drug company marketing has amplified the ‘chemical imbalance’ and low serotonin hypotheses”.
What do we do with this information? For anyone currently on medication – do not stop without discussing with your doctor. Withdrawal symptoms can also occur.
The notion of a chemical imbalance is a simple and appealing theory, especially with a built-in “solution”. However, it ignores the circumstances of our lives and how this impacts our moods and emotions. Effort and time would be better directed to changing the circumstances that lead to depression rather than reducing humans to chemicals to be balanced.
There is not a one-size-fits-all answer to why people may be depressed or in some instances no answer at all. This does not make the current theory correct.
Dr Joe Kosterich – Doctor, Health Industry Consultant and Author
Doctor, speaker, author, and health industry consultant, Joe is WA State Medical Director for IPN, Clinical editor of Medical Forum Magazine, Medical Advisor to Medicinal Cannabis company Little Green Pharma and Course Chair, and writer for Health Cert. He is often called to give opinions in medico-legal cases, has taught students at UWA and Curtin Medical schools and been involved in post graduate education for over 20 years.
A regular on radio and TV, Joe has a podcast – Dr Joe Unplugged, has self- published two books and maintains a website with health information. He has extensive experience in helping businesses maintain a healthy workforce.
Past Chairman of Australian Tobacco Harm Reduction Association, current Vice President of Arthritis and Osteoporosis WA, Joe previously held senior positions in the Australian Medical Association and has sat on numerous boards.
