Wednesday, February 15, 2012

Antidepressants: How Do They Function to Help People Function?

The first step to understanding the value of antidepressants is to understand what they are. Antidepressants are believed to increase the concentration of certain neurotransmitters in the brain in a way beneficial to those suffering from depression. There are four major types of antidepressants and they are all distinguished by the neurotransmitter effects that they produce.

The oldest type of antidepressant is the monoamine oxidase inhibitor, abbreviated MAOI. The inhibition of monoamine oxidase keeps the oxidase enzyme from breaking down norepinephrine, serotonin and dopamine, which are believed to elevate mood. 
Another type of antidepressant is the TCA, or tricyclic antidepressant. Tricyclic antidepressants increase the levels of norepinephrine in the brain and slightly increase the levels of serotonin as well. They are called tricyclic because of their chemical structure, but there are some tetracyclic antidepressants looped into the same group. TCAs work by blocking the reuptake of the two neurotransmitters they affect, resulting in an increased concentration of them in the synapse, which seems to ease depression symptoms.
Then there are selective serotonin reuptake inhibitors (SSRIs) which solely increase the levels of serotonin in the brain. They are the most popular antidepressant because they have the least side effects and drug interactions. The newest antidepressants are the serotonin norepinephrine reuptake inhibitors, which increase both serotonin and norepinephrine levels and are abbreviated SNRIs.


If monoamine oxidase inhibitors work by stopping the enzyme monoamine oxidase from breaking down the important neurotransmitters, how do all these reuptake inhibitors work? After a neuron (brain cell) releases neurotransmitters into the space between the original neuron and another neuron, that original neuron attempts to restore it's stock of that neurotransmitter by re-uptaking some of the neurotransmitters it released. Depressed patients often do not have enough serotonin to go around so, for example, SSRIs prevent the original neuron from taking back the neurotransmitters it released so that the other neuron can detect the chemical signal.

These medicines have revolutionized the treatment of antidepressants since they first came onto the market, but are their effects overwhelmingly good or possibly somewhat negative?

Ogbro, Omudhome. "Antidepressants Drug Class Information by Medicinenet.com." Ed. Jay W. Marks. Web. 15 Feb. 2012. <http://www.medicinenet.com/antidepressants/article.htm>.

 "Tricyclic Antidepressants (TCA's)." PSYweb Complete Mental Health Site. Web. 15 Feb. 2012. <http://www.psyweb.com/Glossary/tca.jsp>.

 "Spotlight SSRI." Office of History, National Institutes of Health. Web. 15 Feb. 2012. <http://history.nih.gov/exhibits/bowman/SSssri.htm>.

 Chemical Structures of Tricyclic Antidepressants. Digital image. MedScape. Web. 15 Feb. 2012. <http://img.medscape.com/slide/migrated/editorial/cmecircle/2001/220/slide09.gif>.

 SSRI. Digital image. Toxipedia. Web. 15 Feb. 2012. <http://toxipedia.org/download/attachments/7143805/SSRI-picture.jpg?version=1&modificationDate=1316517397000>.
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4 comments:

  1. John McCullochFebruary 15, 2012 at 7:47 PM

    Wow,that was informative! I always here about MOAIs in those drug commercials, but now I actually know what they are talking about.

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  2. Savannah MilamFebruary 16, 2012 at 7:45 AM

    Thanks John! I hope you'll come to find that my project will be informative generally.

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  3. Nicholas LalaniFebruary 16, 2012 at 1:41 PM

    Savannah⎯
    As John said, that was indeed very informative. Your topic is very relevant to prospective psychology students who are unsure of whether to pursue the medical career route of psychiatry. I'm very interested to see what you come up with and what opinion you ultimately maintain on this issue.
    On a side note, this particular note on antidepressants is quite relevant to my own project as I will be determining whether depressed diabetics on antidepressants maintain better control of their diabetes than depressed diabetics who aren't treated for their depression. Perhaps I will find no distinct correlation, in which case, I would speculate that my results are indicative of an overall "possibly somewhat negative" effect of antidepressants on the patients. Good luck.

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  4. Savannah MilamFebruary 16, 2012 at 5:44 PM

    I look forward to the progress of your study, Nicholas. I think the results would definitely be an interesting reflection of the effectiveness of these drugs.

    ReplyDelete

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