Encore Presentation: Drug Reactions and the effectiveness of antidepressants

Selective serotonin reuptake inhibitors (SSRIs) are a class of antidepressant drug. You may know them by brand names such as Prozac, Cipralex or Zoloft. In Canada alone, antidepressants are a $1.7 billion market with doctors handing out more than 40 million prescriptions a year.

But some experts now suggest SSRIs don’t work as well as drug companies claim.

Dr. Irving Kirsch is a medical researcher at Harvard University who has studied clinical trial data of five popular antidepressant drugs. Kirsch says his work shows that, for most patients, there’s a “clinically insignificant” difference between antidepressants and placebos.

“What we found was that the difference between drug and placebo was very, very small,” says Kirsch. “It was so small that it would not be meaningful in anybody’s life.”

16×9 obtained internal documents of several drug companies that bolster Kirsch’s research claims. For instance, internal trials conducted by Pfizer on its antidepressant drug Zoloft found “there is still no striking evidence of beneficial drug effect with placebo often being the superior treatment.” Yet Zoloft was approved and went on the market anyway. Pfizer declined 16×9’s interview request to discuss Zoloft, instead sending a statement that said, in part “There is extensive science supporting the safety and efficacy of Zoloft and the medicine carries accurate, science-based and FDA approved information on its benefits and risks.”

Story continues below advertisement

In one of its early clinical trials Prozac manufacturer, Eli Lilly, concluded, “none of the eight patients who completed the four-week treatment showed distinct drug-induced improvement” and “there have been a fairly large number of reports of adverse reactions.” Company documents from 1979 even say some patients on Prozac “have converted from severe depression to severe agitation with a few days.”

Dr. Peter Breggin is a psychiatrist and a staunch critic of antidepressants. Breggin says he saw internal Eli Lilly documents regarding Prozac and discovered something else interesting about the drug.

“In fact it was so stimulating that Eli Lilly cheated and started giving patients tranquilizers, addictive tranquilizers, while they were taking Prozac,” explains Breggin. “That was against the rules.” Eli Lilly declined 16×9’s request for an interview sending a statement that said, in part, “There is a substantial body of rigorous scientific evidence demonstrating the pharmacological efficacy of antidepressants in treating depression.”

Regulators, such as Health Canada and the Food & Drug Administration (FDA) in the U.S., are responsible for assessing pharmaceuticals for the consumer market. But some experts claim these regulators will approve drugs even if the evidence from clinical trials shows they’re only slightly better than placebos. The FDA, for example, will approve a drug on the basis of only two positive clinical trials.

It’s difficult to know what’s required for drug approval in Canada because the Heath Canada branch that assesses drugs doesn’t divulge how it reaches its decisions. Health Canada refused to talk with 16×9 about their drug approval process.

Story continues below advertisement

Dr. Joel Lexchin, a professor of health policy at York University in Toronto and an expert on the regulation of drugs, says “all you have to really show is that it’s better than nothing, and it’s relatively safe,” And he says, “If those criteria have been fulfilled Health Canada puts the drug on the market.”

Dr. Michelle Brill-Edwards is a former senior physician at Health Canada who advised on the safety of drugs. She resigned in the mid-90s after she says she became disillusioned with how the agency functioned – one of her complaints being the agency’s lack of transparency.

“The secrecy afforded to companies is extraordinary and completely against the public interest,” says Brill-Edwards. “It’s our tax dollars that fund Health Canada despite the fees that are being paid as well by the industry so we should have a right of access but we don’t.”

Dr. Irving Kirsch says it’s a matter of money. “These companies are in business to make profits,” says Kirsch. “Anyone who’s not that severely depressed, you’re not seeing any clinically significant benefit at all. And when you get down to the level of moderate and mild depression…you’re seeing zero chemical benefit.”

Don’t miss an encore presentation of “Drug Reactions” this Friday.

Sponsored content