How the Biological Clock Works
This is one of the most impressive science stories I know. Everybody knows they have a clock -- because everyone knows what it's like to try to get up at 4 am when you're used to getting up at 7! You just don't feel right.
How does your body know what time it is? How does your clock shift, if you fly to London? (okay, you Londoners; how about when you fly to San Francisco?)
Turns out your body is using a biological version of an ancient trick, the water clock: a process that takes a very consistent amount of time can be used as a clock. Your body is using some very basic cellular tools as a clock: transcribing DNA, and turning the resulting mRNA into a protein.
The cool part is what happens next: how that protein regulates the process itself. And the coolest part is being able to see how the whole thing works, thanks to the work of some dedicated biologic researchers. For some basic illustrations, and the rest of the story, try this essay on How the Biological Clock Works.
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How does your body know what time it is? How does your clock shift, if you fly to London? (okay, you Londoners; how about when you fly to San Francisco?)
Turns out your body is using a biological version of an ancient trick, the water clock: a process that takes a very consistent amount of time can be used as a clock. Your body is using some very basic cellular tools as a clock: transcribing DNA, and turning the resulting mRNA into a protein.
The cool part is what happens next: how that protein regulates the process itself. And the coolest part is being able to see how the whole thing works, thanks to the work of some dedicated biologic researchers. For some basic illustrations, and the rest of the story, try this essay on How the Biological Clock Works.
6 Comments:
While I respect Dr. Healy's concerns, he is on record of thinking that the prevalence of Bipolar disorder is low. He could also be accused of bias in his own research. For example in paper " The impact of mood stabilizers on bipolar disorder: the 1890s and 1990s compared", he seems to conceintly ignore many factors that may contribute to the increase. Factors as obvious as increasee access to care, better recognition, eaiser transportation to care, ability to pay for care or even the fear of the "Freeman procedure".
As you mentioned, the introduction of SSRI's may be responsible for unmasking bipolar disorder. So while agreeing that the FDA may react poorly, perhaps instead of an either or situation it should be used as an opportunity to awnswer why.
Strangest thing: somehow living between the Atlantic and the English Channel, i.e. the UK, seems to be associated with a diagnostic perspective that finds that low prevalence of bipolar disorder you mention. Of course there are exceptions but you're certainly right about Dr. Healy.
And I also agree with your comment that the FDA's actions are probably best viewed as potentially including both good, well-meaning effort *and* significant influence by the pharmaceutical companies; and that perhaps we should be looking for ways to see how that influence is being applied.
The hearings on antidepressants and suicidality back in 1991 seemed to have a different tone than those of the last several years, so perhaps there has been a shifting of these winds in that time, at least somewhat. I hope so, as one of the most important hearings is coming up: considering whether a warning is warranted for adults as well as kids.
Thanks for your comments.
JP
" Strangest thing: somehow living between the Atlantic and the English Channel, i.e. the UK, seems to be associated with a diagnostic perspective that finds that low prevalence of bipolar disorder you mention. Of course there are exceptions but you're certainly right about Dr. Healy.
"
The very fact of having Dr. Akiskal on this side of the pond is enough to weigh the stats :). Seriously though, I seem to recall reading somewhere (DR. Manji?) that lithium is utilized more in Europe than in NA. If that utilization extends to unipolar depression as well perhaps it explains the discrepancy. As an adjunct to an AD for MD it would possibly prevent those whose BD was unmasked by SSRI's to remain with a "uni" diagnosis.
(Sorry, if anyone is trying to follow this thread, it originated with the blog-post on Antidepressants and Suicidality in Adults. )
Agree again, re: Dr. Akiskal, and yes you're right, Dr. Manji and others have made that comment about lithium's use in Europe, In this case, I think the relative underuse of lithium in the U.S. might be more clearly laid to the heavy advertising here of alternative "mood stabilizers" (though none meet the definition of that term so well as lithium).
Interesting thought you have there about the Europeans -- if you call it MD but treat it with lithium, then it may not matter so much, the diagnostic difference. I'll keep my eye out for any evidence that this is what they're actually doing (frankly, I doubt it, as there is so much stigma against lithium, it's hard to get folks with MD to take it, but I'll see...)
JP
Sorry to disturb again but, the BP kids interview with Dr. Manji (linked on your site) might shed some light on the difference between the continental diagnosis difference.
"The older European studies are suggesting that in recurrent unipolar depression and bipolar disorder that run in families, treatment response is similar (i.e., they respond to lithium treatment), "
This raises the question does the more prevalent use of lithium alter the course of BD so as to dampen manic/hypomanic episodes? In doing so would that prevent the "graduation" to a BD diagnosis? And lastly would doctors in North America initially classify "recurrent depression" as unipolar in the first place?
Dang, you're good. Agree again: on the relevance of Manji's comment and the way that does indeed raise the question, which is very important to consider: might one actually be able to prevent some sort of "progression" into bipolarity from apparent unipolarity using lithium? And secondly, especially if that's so, might American doctors be instead pushing people along that continuum by recognizing recurrent depression as unipolar rather than as some sort of step in the direction of bipolarity?
All still largely speculative unfortunately. My Australian correspondent (head of a mood disorder clinic) I think would very flatly object to this notion of progression and the implications you've pointed out with these questions.
JP
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