Map of life expectancy at birth from Global Education Project.

Monday, March 06, 2006

You gotta believe!

There has been some controversy recently about how important the placebo effect really is, and indeed whether it even exists after all. But it seems pretty clear that it does exist, and can be fairly powerful, at least in alleviating depression and pain. As a matter of fact, readers may recall that the much touted randomized controlled trial that supposed showed that St. John's Wort is ineffective against depression also found that placebo was more effective than Zoloft. For some mysterious reason, the latter finding was generally ignored. Hmm.

Anyhow, research reported recently in the British Medical Journal finds that, over a period of several weeks, sham acupuncture (in which a device like one of those stage daggers that retracts into its sheath is used to make people believe they are being stuck with needles), is more effective than a phony pill in relieving arm pain from overuse injuries. Since there is a difference between the effects of the two procedures, there must be a real placebo effect, although we don't have a comparison with no treatment at all, so we don't know exactly how effective it is. I must say, however, that the improvement people in both groups experienced over 8 weeks was substantial.

The real pill to which placebo was compared in this trial was the antidepressant amitriptyline, brand name Elavil, which can have pretty serious side effects, to whit "Anticholinergic effects (e.g. dry mouth, blurred vision, urinary retention, constipation, palpitations, tachycardia, associated sublingual adenitis or gingivitis). Weight loss or gain. Tinnitus, drowsiness, nervousness, insomnia, Hypotension, dizziness, rash sweating, confusion, mania, psychosis, heart block, arrhythmias, extrapyramidal symptoms. Gastric upset. Endocrine effects (e.g. changes in libido, impotence, gynecomastia, galactorrhea). Rarely, bone marrow depression, hepatic toxicity, seizures, peripheral neuropathy, severe cardiovascular effects in patients with cardiac disease, photosensitivity, Dysarthria, stuttering, renal failure. Withdrawal symptoms."

I'll stick with the cornstarch. Take two aspirin if you're really hurting.

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