Posted by Eddie Sylvano on October 5, 2003, at 15:22:43
In reply to Re: My grand theory about SSRI vs Tricyclics » stjames, posted by DSCH on October 4, 2003, at 13:11:24
I've read at least a dozen times now about studies suggesting that antidepessants' main utility is their inducement of neuronal growth in the hippocampus. It takes several weeks for the growth to mature, and the researchers believe that this is why the antidepressant effects of ADs don't manifest until the 3th or 4th week. The most recent article I read was an experiment on mice. Now, I don't know hoe scientists can accurately gague dperession in mice, but they took some depressed mice, gave them SSRIs, and somehow killed off any new hiccocampal growth that follwed. The control group was given SSRIs and left alone, the reult being that the neuronaly pruned mice didn't show any improvement.
The articles also seem to be uniform in their assessment that untreated depression shrinks the hippocampus. The longer depression is allowed, the worse the damage, and the harder to reverse. After a successful treatment of depression with drugs, discontinuation of the drugs allows the shrinkage to begin anew, leading to a relapse months or years alter, depending on the extent of the prior treatment and previous brain condition. None of the articles ever mention what is causing the atrophy of neurons to begin with, though stress and the chemicals relased during stress (cortisol) are implicated. The hippocampus is associated with the formation of memory, motivation, and emotional response (mood). Here's the first link I found on google:
http://ivy_league0.tripod.com/rhyme_of_the_ancient_wanderer/id69.htmlIt seems that the hope for future drugs is to identify the mechanism by which current antidepressants cause neuronal regrowth (which is incidental to their immediate chemical effect), and create drugs which more specifically (and potentially more quickly) facilitate growth.
poster:Eddie Sylvano
thread:265309
URL: http://www.dr-bob.org/babble/20031004/msgs/265742.html