[lit-ideas] Re: Say wha?

  • From: Mike Geary <jejunejesuit.geary2@xxxxxxxxx>
  • To: lit-ideas@xxxxxxxxxxxxx
  • Date: Sun, 14 Aug 2011 21:01:46 -0500

And then there's this to consider:  all those who were taking
antidepressants were alive, and all those who died were alive as well (until
they died), so the obvious question is does life cause death?  or
antidepressants? Or both.

Mike Geary
in murky Memphis

On Sun, Aug 14, 2011 at 6:00 PM, Donal McEvoy <donalmcevoyuk@xxxxxxxxxxx>wrote:

>   Taking anti-depressants may be called 'X' and an increased risk of
> stroke (from some base rate) may be called 'Y'. Where there is a correlation
> between an 'X' and a 'Y', there are a number of possible explanations for
> this correlation other than 'X' causes 'Y'. One is coincidence; another is
> 'Y' causes 'X' (perhaps those with an increased risk of stroke have a
> physiological problem that is also liable to make them depressed and so more
> likely to be taking anti-depressants) and another is that the correlation is
> explained by a 'Z', which causes both 'X' and 'Y' (imagine 'Z' is a virus
> that causes physiological damage that at once raises the risk of stroke and
> the risk of depression). And these basic alternatives may be multiplied
> because there may be multiple and interacting causes: 'X' and 'Y' may
> correlate only if A, B, & C hold, and then not if P, Q & R do not hold etc.
> This indicates why a correlation is only a starting-point for a further
> causal investigation.
> 'Double-blind' testing has more to do with reducing experimenter bias than
> with the problems of working out whether a correlation between an 'X' and a
> 'Y' is causal or coincidental, and, if causal, whether the causal
> explanation starts from 'X', or from 'Y', or from some 'Z'. Etc.
> Being difficult about questions of proof may, however, be motivated less
> than by a desire for scientific rigour than a desire to protect a vested
> interest: as in the tobacco industry's attitude to the correlations between
> smoking and various ailments. Caveat emptor.
> The trickier question is placing any putative risk in proper perspective,
> as this requires detailed examination of all relevant data: e.g. if only 1
> in a million normally have a stroke, then if 2 in a million on
> anti-depressants have a stroke, then it could be said taking
> anti-depressants doubles the chance of having a stroke - but as the risk is
> still only 1 in every half million it might be thought worth running
> (because of the increased risks if anti-depressants are not taken) or
> negligible. The way these things are reported in the press normally raises
> more questions than are answered, given the paltry information in the
> report.
> You may also find your doctor is not of any great help either, although
> when it comes to the vital question of putting these risks in proper
> perspective they aught to be (or, according to JLS but not me, aught to burn
> a letter; if they do, Eric advises they do not post it).
> Donal
> London
> --- On *Sun, 14/8/11, Julie Krueger <juliereneb@xxxxxxxxx>* wrote:
> From: Julie Krueger <juliereneb@xxxxxxxxx>
> Subject: [lit-ideas] Say wha?
> To: lit-ideas@xxxxxxxxxxxxx
> Date: Sunday, 14 August, 2011, 19:13
> Can somebody parse this for me?
> <<"Although we found women who took antidepressants were at higher risk, I
> don't have anything to indicate it's because of the medications," she
> says.>>
> http://yourlife.usatoday.com/health/medical/womenshealth/story/2011/08/Depressed-women-have-higher-risk-of-stroke/49931142/1?csp=ylf
> Julie Krueger

Other related posts: