Wednesday, March 22, 2006

Drugs Cause Bad Science

Here's an article I just saw today claiming that MDMA (Ecstasy) can cause permanent memory loss. This is a study that was published in a prestigious journal and covered widely by the press -- with provocative comments by the lead author warning that the study's message is "loud and clear" that users will not recover memory and learning capacity.

But look at the study.

Fifteen subjects. Half of them (8) were not using one year later. The article says that, "In all of the former users who had been abstinent for at least 32 weeks, test scores improved compared with their scores one year previously. However, some individuals' scores stayed the same." Presumably the "some individuals" refered to are those who had not been abstinent for at least 32 weeks -- as ALL those who had been improved.

So what can we conclude from this study?
1). Nothing. 15 subjects is far short of anything approaching statistical validity.
2). All those who hadn't used MDMA for 8 months scored better than they had a year previously, so we might conclude that there is evidence that memory recovers when MDMA use stops -- but that it takes several months for the recovery to get under way.

But that's not the headline, nor is it what the lead author says the conclusions are. He says that if you stop, "your memory may or may not recover." But ALL of those who stopped experienced improved memory over a year previously, so his conclusion is directly opposed to what the study shows.

It doesn't matter though, because my point is that shitty, sloppy bullshit science gets widely published and editorialized when the message is what society wants to hear. Next time someone tells you that science is about the search for truth, keep that in mind.

Ecstasy-related memory impairment can be permanent
Wed Mar 22, 2006 12:33 PM ET

By Anne Harding

NEW YORK (Reuters Health) - Taking the drug Ecstasy can impair memory and learning, but giving up the drug can stop the slide in mental capacity, a new study shows. However, researchers also found evidence that in heavy Ecstasy users, the effects on memory may persist even after they quit.

"The message should be loud and clear that if you're using a lot, you're not going to recover learning and memory," Dr. Konstantine K. Zakzanis of the University of Toronto at Scarborough, the study's lead author, told Reuters Health.

Zakzanis and his colleagues had previously shown that people who used Ecstasy, also known by the chemical name MDMA, experienced a decline in their memory over a one-year period. The 15 study participants' reported using the drug from 3 to 225 times over the course of the year.

The researchers looked at the same 15 people after another year had passed. Seven were still using the drug, while eight had become abstinent. The researchers evaluated their memory and learning using three tests, including the Rivermead Behavioral Memory Test, which is designed to evaluate everyday memory function.

In all of the former users who had been abstinent for at least 32 weeks, test scores improved compared with their scores one year previously. However, some individuals' scores stayed the same. Current users showed continued decline, with more frequent and longer-term use of the drug tied to greater loss of memory and learning function.

The worst impairments were seen in episodic memory, meaning the sort of memory a person uses while watching a news story on television and then trying to describe it to another person later.

"The general conclusions that one can make are that if you stop using, your memory won't get worse," Zakzanis said. "Depending on how much you've used, your memory may or may not recover."

Zakzanis pointed out that damage to memory and learning is just one harmful aspect of Ecstasy use, which also has been tied to depression.

SOURCE: Neurology 2006;66:740-741.

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