Mechanisms of Antidepressant Action: In Brief

By Keltner, Norman L. | Perspectives in Psychiatric Care, April-June 2000 | Go to article overview

Mechanisms of Antidepressant Action: In Brief


Keltner, Norman L., Perspectives in Psychiatric Care


After a 4-year hiatus, this column returns as a regular fixture of Perspectives. As before, the emphasis will be on biological aspects of understanding and/or treating mental disorders. It is an interesting time to reintroduce this column, because now we can look back on the "decade of the brain" in its entirety and begin assessing its impact on psychiatric care.

While the congressional pronouncement heartened many of us concerned with psychiatric nursing's pre-1990s reluctance to embrace biological constructs, it will be up to those with a greater breadth of vision to distill the decade's overall impact. It seems fair to say, even this early in the decade's review, that psychiatric nursing took the clarion call seriously and made substantial inroads into addressing the specialty's brain-related knowledge deficits. For example, in 1990 some psychiatric nursing textbooks still were alienating families with the suggestion that bad mothering (e.g., the schizophrenogenic mother) caused schizophrenia. You will not see such concepts in textbooks today. Further, all textbooks and journals now pay closer attention to psychotropic drugs and psychobiology than before the decade of the brain. Whether the overall field of psychiatric care evolved as hoped will be debated, but it is clear that important changes occurred in psychiatric nursing during those 10 years. This relaunching of Biological Perspectives aims at continuing a contribution to this momentum. In that vein, we address an area of psychiatric care undergoing significant change during the decade of the brain--antidepressant therapy.

During the 1990s and just before, a number of new antidepressant drugs were introduced: sertraline (Zoloft), paroxetine (Paxil), fluvoxamine (Luvox), bupropion (Wellbutrin), venlafaxine (Effexor), nefazodone (Serzone), mirtazapine (Remeron), and citalopram (Celexa). As new antidepressants, they empowered clinicians because they were, in Preskorn's (1994) words, "rationally developed." This rational development, or molecular targeting, starkly contrasted the serendipitous "discovery" of monoamine oxidase inhibitors (MAOIs) in 1952 (a better antituberculosis drug was sought) and tricyclic antidepressants (TCAs) in 1956 (a better antipsychotic was the goal). Prior to the selective serotonin reuptake inhibitors (SSRIs) and other "new" drugs mentioned above, clinicians had limited choices--for instance, when a TCA failed, the clinician was forced to stay "within class" or switch to the multiproblemed MAOIs. Since the numerous antidepressants available today provide improvement over the limited options of just a few years ago, it seems prudent to review just what makes them different from each other.

As it turns out, the array of antidepressant medications available today can be distinguished by at least seven distinct mechanisms of action; see Bezchlibnyk-Butler & Jeffries (1997) and Stahl (1998).

1. Blocking enzymatic breakdown. The MAOIs were the first antidepressants "discovered," and the only antidepressants inhibiting neurotransmitter breakdown as a primary mechanism of action. Monoamine oxidase can be found in the liver, intestines, and terminals of monoamine-producing neurons. This enzyme can be further differentiated into type A (metabolizes nor-epinephrine and serotonin) and type B (metabolizes dopamine). MAOIs inactivate monoamine oxidase, resulting in increased levels of monoamines (dopamine, norepinephrine, serotonin). The older, nonselective drugs (e.g., phenelzine, tranylcypromine) inhibit both types A and B, while newer agents such as moclobemide (inhibits type A) and selegiline (inhibits type B) are more selective. MAOIs are known to cause serious interactions with tyramine-containing foods and with a number of drugs, particularly indirect-acting sympathomimetics and serotonin-enhancing agents. MAOIs have a narrow therapeutic index.

2. Nonselective inhibition of norepinephrine and serotonin uptake. …

The rest of this article is only available to active members of Questia

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

Mechanisms of Antidepressant Action: In Brief
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Author Advanced search

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.