Friday, January 27, 2012

No Evidence that a Serotonin Imbalance Causes Depression, or that Antidepressants Improve Depressive Symptoms

There has never been a single study that conclusively links serotonin levels (low, high, or normal) with depression, so using drugs to increases serotonin is completely unrelated to the subjective experience and the objective brain chemistry of the patient. This is not new information - I've presented this argument before.

In 2006, Joanna Moncrieff and David Cohen wrote an editorial essay for PLoS Medicine, Do Antidepressants Cure or Create Abnormal Brain States? The gist of their article is articulated in the summary:
Antidepressants are assumed to work on the specific neurobiology of depressive disorders according to a “disease-centred” model of drug action. However, little evidence supports this idea. An alternative, “drug-centred,” model suggests that psychotropic drugs create abnormal states that may coincidentally relieve symptoms. Drug-induced effects of antidepressants vary widely according to their chemical class—from sedation and cognitive impairment to mild stimulation and occasionally frank agitation. Results of clinical trials may be explained by drug-induced effects and placebo amplification. No evidence shows that antidepressants or any other drugs produce long-term elevation of mood or other effects that are particularly useful in treating depression.
Moncrieff J, Cohen D. (2006). Do antidepressants cure or create abnormal brain states? PLoS Med 3(7): e240. DOI: 10.1371/journal.pmed.0030240

The recent discussion of this topic began with an NPR Morning Edition segment, When It Comes To Depression, Serotonin Isn't The Whole Story, that examined the "chemical imbalance theory." Nearly all of the psychiatrists they spoke with admitted that there was never any real evidence that supported the "low serotonin causes depression" hypothesis.

Many listeners were outraged that these same doctors still tell patients that their depression is caused by low serotonin levels and that drugs correct that imbalance.

Jonathan Leo, Ph.D. and Jeffrey Lacasse, Ph.D. at Mad in America, a very cool new site run by Robert Whitaker (see his article, The chemical imbalance theory of mental disorders was disproven long ago — as well as Marcia Angell (former Editor in Chief of The New England Journal of Medicine), whose pieces in the New York Review of Books mentions that the chemical imbalance story didn’t appear to have merit), fired off a nice post in response:

Psychiatry’s Grand Confession

The psychiatry profession has finally come clean and confessed on a national media outlet that there is no evidence to support the Serotonin Theory of Depression. Today, on NPR’s Morning Edition there is a segment about the chemical imbalance theory, and virtually all the psychiatrists who are interviewed acknowledge that the there was never any evidence in support of the idea that low serotonin causes depression. But then, amazingly, they go on to say that it is perfectly fine to tell patients that serotonin imbalance causes depression even though they know this isn’t the case.

Several years ago in PLoS Medicine we wrote a long piece about the serotonin theory and the disconnect between what research psychiatrists say in professional journals and textbooks and what the advertisements say. While the advertisements presented the theory as scientific fact, the scientific sources clearly did not. Given the enormous marketing programs that pushed this theory combined with the media’s lack of skepticism, we were sympathetic to the general public who could hardly be faulted for thinking that theory had some foundation in fact. Following the publication of our piece a reporter contacted us and suggested that we were attacking a well accepted theory. We pointed out to the reporter that we weren’t attacking a sacred cow but that instead we were pointing out the mainstream psychiatry didn’t even accept this theory. We urged the reporter to contact the FDA, NIMH, APA, etc and ask them about the science behind the advertisements. He did, and as expected, an expert from the FDA explained that the theory was really just a metaphor. The problem is that patients who heard their physician explain the serotonin theory thought they were hearing real science. They weren’t told it was a metaphor and hence thought it was a fact. When a doctor talks about high cholesterol, diabetes, or hypothyroidism, they are talking about scientific measurement, not a metaphor. How is a patient with high cholesterol and depression who listens to their doctor’s explanation of their conditions supposed to know when the doctor has moved from science to metaphor?

Several months ago Ronald Pies published an interesting article in Psychiatric Times entitled, “Psychiatry’s New Brain-Mind and the Legend of the Chemical Imbalance.” Pies, just like the experts on NPR, acknowledges that the Chemical Imbalance theory is not true. However, according to Pies, it was the pharmaceutical companies who espoused the theory, and not well-informed, practicing clinicians, because the psychiatry community has known all along that the theory is not true.

But if the Psychiatry Community knew all along that the theory was not true, then why did they not clarify this issue for the general public? Shouldn’t they have pointed out to the general public and patients that what the pharmaceutical companies were saying about psychological stress was not true? Why did the professional societies not publicly set the record straight?
Read the whole article.

Some of the most consistent work in this realm has been posted at Beyond Meds - check out these articles:


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