The Serotonin Myth

A myth is a story (either fictional or partially factual) which is used to explain a natural phenomenon or to illustrate a moral or cautionary lesson.

If you go along to your doctor complaining of depression there is a fair chance that you will hear about serotonin. Perhaps the older term "chemical imbalance in the brain" will get a mention too. The idea is that the low levels of serotonin in the brain cause the symptoms of depression. Serotonin is a neurotransmitter which means that it is a chemical that nerve cells use to message one another. If it is in short supply then the brain nerve cells that are dependent on it will not function very well. Many of those cells help to maintain happiness, so when they fail we become unhappy. And if we can just give the serotonin a boost all will be well again. It is a good story - simple, easy to understand, seemingly scientific. But it is a myth....

There is evidence that serotonin is somehow linked to depression, not the least of which is the fact that most of the drugs which help depression do appear to boost serotonin levels. However the truth of the matter is that doctors do not really fully understand the neurochemical basis of depression or indeed most of human behaviour.

Some people object to using a neurochemical model to explain human feelings and behavior because they believe it denies the reality of free will, and that idea challenges some very important ideas regarding morality, ethics and religious belief. Humans clearly do not function as puppets with the strings being pulled by chemicals such as serotonin. Free will is something we all experience and use most of the time. But of course the operation of free will is limited by biological factors. We all have the choice of eating or fasting but most of us could not voluntarily maintain a total fast for much longer than a day, mainly due to the biological drive to eat, which eventually becomes stronger than our willpower. People with drug addiction have a similar problem - while the decision to use drugs is ascribed to a weakness of willpower the biological drive is often more powerful than the will to eat!
In depression a person's ability to make choices is hampered by the biological factors of their illness, but it is far more complicated than just a low serotonin level.

However like ancient myths the serotonin myth serves some important purposes.

Explanation. Myths explain things that need explaining. Most of the explanations of ancient mythology have been superseded by scientific explanations so a modern myth has to be based on a scientific model to have any credibility. Being only partially factual does not matter to a myth.

Morality. Myths provide moral guidance. People with depression often feel guilt and feel that they have done something to deserve their situation. They are often blamed by others for not "snapping out of it". Unfortunately there is a stigma attached to mental illness. Presenting it as a chemical deficiency (like diabetes) excludes blame guilt and morality, which is a good thing.

Action. Myths provide guidance in decision making. The serotonin myth helps guide people to make a sensible decision which is to get treatment for their depression. Drugs which boost serotonin are lifesaving and even cognitive behavioral based therapies sometimes get explained in terms of the fact that these therapies will boost serotonin levels and thus help resolve the depression.

For many people ancient myths are now regarded as "wrong" because the explanations they provide have been replaced by better explanations. But such a judgement ignores the valuable role these stories served in their own time. Similarly I have no doubt that one day the serotonin explanation will be regarded as wrong. However that does not matter to us now as the serotonIn story still has much to offer in the treatment of depression.

Comments

[jenny]

So that means that we can no longer justify sneaking chocolate, cream, double brie by saying it is naturally boosting up our serotonin levels? I discovered a good article here on eating and emotion.
How do you tell the difference between someone who is experiencing sadness/stress (which is often labelled depression) and a more severe depressive illness? As you know I don't like the idea of pill popping for people who are feeling sadness for whatever reason, BUT I know how beneficial medication is for the more severe psychiatric illnesses like manic depression and I have seen the effects when friends with this illness have stopped medication. For the first group of people I'd much rather the counselling approach (although I realise that under our health system people can't always afford to go to counselling) and occasionally this group do benefit from people saying "snap out of it". I frequently come across this in rehabilitation settings where people have been overcome by the sorrow of what has happened to them and as a consequence are in danger of not working on their independence skills because they don't see the point, even though they may still have the physical skills to achieve independent mobilty. Is there any merit in the "you've got to be cruel to be kind" approach? Then again the "protestant ethic" - which I was brought up with - does place a stigma on mental illness, it is assumed that you must keep the "stiff upper lip" in times of stress - even crying at a funeral in public is a no no.... Drowning one's sorrows by eating fat and sugar in the quietness of one's home is preferable to showing emotion in public. Maybe that's why everyone on my side of the family is overweight!

[kyte]

oooh, here's a post I cannot resist commenting on. At length.

SSRIs: In spite of all "evidence" to the contrary, I don't believe SSRIs are good for all types of depression. Once upon a time there was something called "agitated depression". Now they want it to be bipolar illness. Why? Because without that, Epilim would only be used for epilepsy. But if we call Epilim a mood stabiliser, and we call agitated depression "bipolar" then we can sell a lot more Epilim (Sorry, Sanofi). The good old tricyclics worked for agitated depression. But.. oh dear.. someone might overdose on them so we better not prescribe them anymore. Thank god there are some doctors who have a few neurons and who resisted the marketing. SSRIs might be good for some depressions, but you have to wonder at times. Then again... when did it become a bad thing to howl after a massive personal loss, and when did it become necessary to medicate the kind of everyday sadness we all experience at times. Seems to me everyone wants to be happy 24 hours a day, and that ain't gonna happen. Ever.

CBT: In our small circle we use CBT to get people to take responsibility for how they feel, instead of saying "oh woe is me, my life would be perfect if only...". We say that bad things happen to everyone. We say that its not the thing itself that makes you feel bad/depressed or whatever, its what you make of it. Thats why some people dont get miserable over things which make other people miserable. We sometimes use the serotonin explanation if someone demands it. Otherwise we tend to stay away from it because we dont necessarily buy it.

Geoff, you need to start reading Mike Lascelles at Pharmawatch if you have not already.

[Geoff]

Kyte, thanks for the interesting link. As you point out it is a great trap to label as depressed everyone who is unhappy. Similarly many people who think they have migraine in fact have tension headache and many "flu victims" actually have a common cold. I agree that unhappiness is a normal and appropriate human feeling which we will never abolish... but so is pain... and it is expected that a patients pain will be relieved with painkillers while the underlying cause is treated. If we had a drug which could quickly and temporarily relieve unhappiness I wonder how it would be used. Or perhaps people ARE using SSRIs in the hope that they will have this effect?

[kyte]

I think thats the expectation of SSRIs. And indeed some people seem to get some kind of good response. There are some I know who become quite anxious at the prospect of not having their Prozac or (fill in the blank) on board. But that then raises other questions which I won't delve into here. Suffice to say that the word "placebo" springs to mind. I just have this overwhelming feeling that the mystification of psychiatry served a purpose apart from the obvious: that being that once, it wasn't sexy to have an illness of that kind. These days it seems to me like everyone thinks they need to be in therapy. Sometimes I just want to scream "GET OVER IT!!!" or "oh grow up!!" But that wouldn't be professional. So I don't. And I still refuse to have a fluvax.

[Linkadge]

Depression is more than a simple imballence of a particular neurotransmitter. Most severe depression is accompanied by somewhat profound change in key brain structures such as the hippocampus and the frontal cortex.

The changes in hippocampal volume in many depressed patients considerably squelches an individual's ability to see the obvious answers. It is a whole brain disease which can make every day, like your worst day.

Just because you were able to conquer your worst day, does not give you the right to think that others can do similary.

To me, the only people who are truely "well" in this world, are the ones who know depression well enough to never cast jugement on another for feeling helpless.

If you're well and you just want prozac to feel better, go right ahead I say. The brain's homeostatic mechanisms are always one step higher than your foolish desires. Plus, the whole host of discusting side effects will make certain that you get no free ride.

Just my 2 cents.

Linkadge

[Cara Fletcher]

Serotonin doesn't help at all.This is a very common medication when talking about depression but I don't think it's appropriate.I think natural treatments are better decision for depression.

[Zeno Izen]

I take issue with this statement:

"Humans clearly do not function as puppets with the strings being pulled by chemicals such as serotonin."

Scientific evidence suggests that we are in fact mere puppets of our neurochemistry. Free will, it seems, is an illusion created by our brain.

[propecia]

So, the serotonin myth? Was it invented purely to market GSK's baby, Seroxat? But more importantly, did GSK know that patients would become addicted to it, thus earning them pocketfuls of cash?

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What mental illness is someone most likely to be a feces smearer? Is it Autism or Skitsofrenia or something else?