Sunday, October 31, 2004

Prozac and baby mice

...or rats, depending on the reporting. More animal research on Prozac, with an unfortunate lack of details so far. It's hard to know how to assess this article (note, WebMD says "mice," but this article says "rats"):

"Rats given the drug for the first few weeks of life perform poorly on tasks designed to test their confidence and ability to deal with stress, says psychiatrist Jay Gingrich, who ran the study with his colleagues at Columbia University in New York.

"Gingrich's colleague Mark Ansorge assessed the rats' behaviour by placing them in a cross-shaped maze raised above the floor, a test that measures the willingness of the animals to explore an unusual environment. Adult rats dosed with Prozac early in life were less interested in venturing far from their starting point and spent less time moving around. Animal researchers take this behaviour as evidence of abnormal emotional development.

"Related tests revealed that rats given Prozac are also less willing to take risks to earn rewards such as food and take longer to escape unpleasant environments, a sign that they deal poorly with stress. The results were revealed on 26 October at the annual meeting of the Society for Neuroscience, held in San Diego, California. They will be published in the journal Science this week."

I've always tried to emphasize to pregnant patients that we simply don't know about all possible effects of SSRI exposure. When we try to weigh the risks and benefits, we don't know all risks. What usually tips the balance: will there be a mother, and a baby, if we don't use a medicine like prozac? Will suicide or homicide be less likely with the medicine? Have all other options been explored?

I'm no researcher, but I'm not sure how you make the leap from rat behavior to rat emotions. I suppose that if the "risks" were actually risky for the non-medicated rats, such that some were injured by their risk-taking, then the survival rates of prozac-exposed rats might be higher. Just the fact that rat behavior changes, though, is enough to give me pause. We'll have to wait until the research is published this week. And for its real significance, as the article says, we'll have to wait until there is more research on humans who were exposed as fetuses. Our "cautious" prescribing behavior will become yet more cautious. Like the rats (or mice?) treated with prozac, I am exceedingly risk-averse.

(update - my google search reveals more articles saying "mice" than "rats.")

(another update: here's a link to the journal article.
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