Posted by Shawn. T. on March 13, 2003, at 16:09:24
In reply to Re: need for atypical depression research » Shawn. T., posted by Ilene on March 12, 2003, at 20:32:59
Hok- you're welcome. I don't know that I have any suggestions; I'm generally unfamiliar with dealing with the NIH beurocracy.
Ilene- The correlation between migraine and affective disorders applies to both bipolar disorder (moreso with bipolar II) and unipolar depression. Activation of serotonin 5-HT1B/5-HT1D receptors seems to relieve migraine headaches. There is some evidence that decreased serotonin turnover exists in some migraine sufferers. 29-35% of people with unipolar depression exhibit decreased serotonin turnover, so there may be some connection there; that's a purely hypothetical notion, however. 5-HT4 agonists and 5-HT3 antagonists have been shown to be effective treatments for some people with irritable bowel syndrome. 5-HT4 agonists are effective in constipation- predominant IBS, and 5-HT3 antagonists are more effective in diarrhea- predominant IBS. I believe that the effects of serotonin on receptors in the brain may be as important as its effects in the gut; I'm not quite sure about precisely how large of a role serotonin in the gut plays. The S/S genotype of the serotonin transporter gene may be associated with constipation- dominant IBS, and the L/S genotype may be associated with diarrhea- predominant IBS. Migraine sufferers with S/S genotypes may experience more frequent migraine attacks. Note that L stands for "long" and that L alleles are associated with greater expression of serotonin transporters. Different serotonin transporter genotypes may affect unipolar and bipolar disorders as well; age of onset, frequency of episodes, and response to SSRI's may be affected by certain genotypes. Note that my brother has IBS; my mom experiences migraines; my sister may have atypical depression; and I have cyclothymia/bipolar II with atypical depression. Otherwise, I might be a bit less familiar with some of this information. Ask me for any references that you might like to see; I usually include references but am feeling lazy today.
A "modification gene" is a term that I made up; it's basically a gene that modifies the effects of another gene. I'm sure that other people may use similar terms to describe the same thing. Serotonin transporter genotypes do not cause increased susceptibility to any disorders by themselves; they do, however, modify the effects of susceptibility genes. A "susceptibility gene" is one that increases the likelihood that a person will experience a certain disorder. Researchers are careful about implying that susceptibility genes cause certain disorders; neurodevelopmental factors and the presence of other contributing genetic factors are often seen as necessary co-factors in causing various disorders. A susceptibility gene generally encodes a protein, enzyme, or other type of biological substance that may occur in a specific region of the body or in several regions.
I agree that relying solely on PubMed for reference links on my site may create some problems, but I use it for a very specific reason. There are other sites, like Infotrieve, that might even contribute some money to my efforts when people using my site transfer to their site and decide to purchase an article. PubMed recently created PubMed Central to encourage more prevalent free access to journal articles. One cannot access PubMed Central links from databases like Infotrieve's, and I cannot always link to full text articles because the abstract is too new. So I link solely to PubMed so that people might have a greater chance of obtaining a full text article in the future. I personally believe that research funded by tax payers should be available to those tax payers free of charge.
Shawn
poster:Shawn. T.
thread:207835
URL: http://www.dr-bob.org/babble/20030310/msgs/208800.html