Posted by Robert_Burton_1621 on August 20, 2016, at 10:26:25
In reply to Is depression a chemical imbalance? No., posted by SLS on August 5, 2016, at 7:26:57
> Is depression caused by a chemical imbalance?
>
> First, we must establish what we mean when using the word, depression. Depression has many faces. It feels different to different people, as there are many causes and many subtypes of depression. Some people experience a depressed mood as the result of a situation or event in their lives that produces profound sadness. This is sometimes referred to as situational depression, and with a properly functioning brain, one can process the loss and feel good again. The same can be said of bereavement and the grief experienced as the result of losing a loved one. For the purpose of this article, we will talk about Major Depressive Disorder (MDD). MDD is defined as having a depressive episode that lasts for at least two weeks. Unfortunately, most people experience a depression that lasts for months or years. Symptoms usually include:
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> Depressed mood.
> Sadness.
> Low energy and fatigue.
> Lack of interest or pleasure in doing things.
> Lack of motivation.
> Changes in sleep patterns (insomnia or oversleeping).
> Impairments in concentration.
> Slowed thinking.
> Impairments in memory.
> Difficulty making decisions.
> Low sex drive.
> Changes in appetite and body weight (increase or decrease).
> Recurrent thoughts of suicide.
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> Major Depressive Disorder is now considered to be an illness of the brain. But can it be explained as a simple imbalance of brain chemicals? No.
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> Major Depression involves many more aspects of brain function than just the levels of chemicals. Neuroscience has uncovered many physiological abnormalities in the structure and function of the brain. They are too numerous to list here. The major type of cell used by the brain for processing information and communication is the neuron (nerve cell). The chemicals used by one neuron to communicate with another neuron are known as neurotransmitters. These include serotonin, dopamine, and norepinephrine. There are more, though. The exchange of neurotransmitters is only one of the ways in which neurons communicate with one another. There are even ways in which a neuron communicates with itself within the cell. However, these aspects of Major Depressive Disorder are rarely conveyed to the public. Instead, MDD has historically been explained as a simple chemical imbalance in order to make it more understandable, and to emphasize that the illness is biological in origin. It seems that the public may have outgrown this teaching tool.
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> More recently, a problem has resulted from the continued use of the term, chemical imbalance to explain to the public the biological origins of Major Depressive Disorder. Because scientists have determined that MDD is not a disorder caused exclusively by chemical imbalances, some people have jumped on this statement in order to pursue their agendas to claim that MDD does not have any biological components at all. While it is true that an episode of Major Depression can be triggered by a situational depression or other psychosocial stresses, this is only possible if there are any pre-existing genetic or other biological vulnerabilities. In other words, just because MDD is no longer thought of by scientists to be the result of a simple chemical imbalance does not mean that there are no other biological processes responsible for it. There are. MDD can also be made understandable by thinking of the brain as a universe of neurons acting like computer processors connected by a network of circuits. The routing of circuits between brain structures is more important than which neurotransmitters are being used between neurons to send messages. So the next time someone tells you that depression is not biological in origin because the chemical imbalance theory has been proven wrong, you will understand that there is faulty logic involved in coming to that conclusion.
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> - ScottJust very briefly, and inadequately:
This is very thought-provoking, Scott.
While you proceed on the assumption that MDD is a clinically (and not merely nominally) valid disorder (condition? disease?), I have come to the view that the beginning of wisdom in clarifying the nosology of so-called "depression" is to recognise that "it" is not monotypic. Nor is "it" an entity whose internal distinctions can be merely represented on a symptomatological "spectrum" of severity. I suspect the research into depressive nosology is only just beginning. A lot of very interesting and relevant work (including neuropsychiatric work) in this area is being done by the Black Dog Institute.
I shall respond more fully soon.
Scott's raised an issue which should be at the forefront of our minds on this site, at least among those of us who have been categorised as, or would categorise ourselves as, "treatment-resistant" (this is a description which itself demands rational dissection).
poster:Robert_Burton_1621
thread:1091155
URL: http://www.dr-bob.org/babble/20160819/msgs/1091470.html