Low Serotonin Levels Don’t Cause Depression

[bananas]

http://psychcentral.com/blog/archives/2014/09/13/low-serotonin-levels-dont-cause-depression/

Low Serotonin Levels Don’t Cause Depression
By John M. Grohol, Psy.D.

One of the leading myths that unfortunately still circulates about clinical depression is that it’s caused by low serotonin levels in the brain (or a “biochemical imbalance”). This is a myth because countless scientific studies have specifically examined this theory and have come back universally rejecting it.

So let’s put it to rest once and for all — low levels of serotonin in the brain don’t cause depression.

Let’s find out why.

This isn’t the first time we’ve had to debunk this myth. We last did so in 2007 — 7 years ago — pointing out that most people’s (even doctor’s!) belief that low serotonin causes depression is a result of pharmaceutical companies’ successful marketing. It’s a message they repeatedly hammered home, making it one of the most successful marketing messages-turned-into-fact ever done on Madison Avenue.

However, you may be reading this article to get to the punch line: So if low serotonin levels don’t cause depression, what does? Here’s the short answer — researchers still don’t understand what causes depression. We have a lot of theories still in the mix and still being researched, but none of them have resulted in one, conclusive answer.

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If a doctor suggests this is the cause of your depression, and all you need is an antidepressant like Prozac, point them to this article. And please take a moment to share this on Facebook and twitter. It’s an widespread myth that dumbs down depression that we need to put to rest once and for all.

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[tridim]

1. I believe depression starts in the gut, which is where most serotonin is made (or not).

Lots of modern research agrees. It's pretty much a law, if your gut is unhappy, so are you.

Resistant starch (potato starch) changed everything for me and my bacteria. We're all happy now.

[bananas]

2. The gut is called "the second brain"

And yes, "More than 90% of the body's serotonin lies in the gut, as well as about 50% of the body's dopamine":

http://en.wikipedia.org/wiki/Enteric_nervous_system

<snip>

The enteric nervous system has been described as a "second brain" for several reasons. The enteric nervous system can operate autonomously. It normally communicates with the central nervous system (CNS) through the parasympathetic (e.g., via the vagus nerve) and sympathetic (e.g., via the prevertebral ganglia) nervous systems. However, vertebrate studies show that when the vagus nerve is severed, the enteric nervous system continues to function.[15]

In vertebrates the enteric nervous system includes efferent neurons, afferent neurons, and interneurons, all of which make the enteric nervous system capable of carrying reflexes and acting as an integrating center in the absence of CNS input. The sensory neurons report on mechanical and chemical conditions. Through intestinal muscles, the motor neurons control peristalsis and churning of intestinal contents. Other neurons control the secretion of enzymes. The enteric nervous system also makes use of more than 30 neurotransmitters, most of which are identical to the ones found in CNS, such as acetylcholine, dopamine, and serotonin. More than 90% of the body's serotonin lies in the gut, as well as about 50% of the body's dopamine, which is currently being studied to further our understanding of its utility in the brain.[16]

The enteric nervous system has the capacity to alter its response depending on such factors as bulk and nutrient composition.[citation needed] In addition, ENS contains support cells which are similar to astroglia of the brain and a diffusion barrier around the capillaries surrounding ganglia which is similar to the blood–brain barrier of cerebral blood vessels.[17]

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[A Little Weird]

3. Interesting

I have known people whose condition dramatically improved after taking SSRIs but it doesn't sound like it's as straightforward as I believed it to be.

[Old Crow]

4. I would like to raise a caution regarding this article...

I say that for several reasons, first among them being that the author is neither a medical doctor nor a researcher. He is not qualified--nor legally allowed--to prescribe antidepressants. He holds a doctorate in psychology, which is not a medical degree. Yet by making statements such as &quot R)esearchers still don’t understand what causes depression. We have a lot of theories still in the mix and still being researched...," he's giving the impression to readers that either he's a medical doctor or a medical researcher.

A second problem I have with the piece is the title: "Low Serotonin Levels Don’t Cause Depression." If the author of this article can prove that statement--"Ladies and gentlemen, I can categorically state that low serotinon levels have no effect at all on depression"--he could land himself a top position in a university and, quite possibly, the Nobel Prize for Medicine. Finding one or two animal studies that found no link between serotonin levels and depression is a long, long, long way from disproving a correlation in humans. A more responsible and scientifically accurate statement would be "Researchers Uncertain What Role Low Serotonin Levels May Play in Depression."

The author does make the important point that pharmaceutical companies were advertising their products as if a clear causal link between low serotonin levels and depression had been identified, when none has. So I do think the article has some value--provided it's taken with the proverbial grain of salt.

[Nitram]

5. All I know is, taking a SSRI has improved my life.

There may be some over-simplification going on here.

[Old Crow]

6. +1 (although I no longer take one) (EOM)