Prescription drug advertisements are a risky business.
Marketers for direct-to-consumer medication have — perhaps inadvertently — tricked consumers into downplaying the risks of a drug by presenting too many of them.
A new study, published in the journal Nature Human Behaviour by researchers at the University of Michigan, reveals that when a drug advertisement throws too many risks at you — we all know the oft-parodied endless scroll of side effects with a speedy narrator — the less risky a drug is perceived to be by a potential consumer. It’s a psychological phenomenon called “the dilution effect.”
The researchers performed a series of experiments involving more than 3,000 participants. In one experiment, about 800 people listened to an ad for Cymbalta, a drug to treat depression. Those who listened to the full ad, with both major and minor risks, thought the drug was less risky than those who listened to a version of the commercial that listed only the severe side effects.
Drug ads are required by the Food and Drug Administration to list their risks along with the drug’s benefits, but savvy marketers have perhaps found that the more risks the commercial or print ad lists, the better for their brand because the smaller side effects dilute the larger risks.
The study found that when only the severe side effects are listed, a potential consumer will immediately think the drug will cause them harm, but when heart disease and stroke are listed with headache and dry mouth, the drug is seen as overall less risky.
Both types of side effects are important, the study says. The severe side effects, which are rarer, are important in a potential consumer judging the major risk factors of a drug. But the lesser side-effects are typically more common, so consumers also need to know they could happen. Both are necessary for weighing the cost of the adverse side effects to the benefits of the prescription.
The study says that this means medication risk communication may need to be divided between severe and less severe risks. One of the experiments in the study listed all the side effects but bolded the more severe ones. Consumers who saw that list judged the drug just as risky as those who saw only the severe side effect lists. But the study says more work needs to be done to say for certain if that method is better overall.