It's only fair to share…

There is a tendency in western medicine to have a reductionist approach. Everything can be reduced to a single cause, or at least a predominant one. In turn this approach lends itself to a single treatment – usually a pharmaceutical agent. This is a variation of 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 blood stream and seeing a lower number on a pathology result was not translating into lower rates of heart disease.

The least understood part of 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 for 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 of the selective serotonin reuptake inhibitors (SSRI’s) 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 where he challenged 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 appositive effect were not. Initially, published data had shown medications to be significantly better than placebo. When all data (published and unpublished) was examined, it was found that in mild and moderate depression SSRI medication was no more effective than placebo.

In other words, people got better but 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 has 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 benefit is questionable at best.

Medscape notes surveys show over 80% of the public believe the serotonin theory which was widely publicised in the 1990’s with the introduction of SSRI’s. 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 mood and emotion. 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.