Credit: iStock

Americans are increasingly reliant on prescription medicines.

According to the latest available data from the Centers for Disease Control (CDC), 47.3 percent of Americans have taken at least one prescription drug in the last 30 days, and 10 percent have taken five prescription medicines or more. Moreover, the percentage of Americans taking drugs for high cholesterol has roughly doubled in the last ten years, while the share of people on anti-depressants has grown by about a third.

Americans are living longer, and the incidence of chronic diseases like diabetes and high blood pressure have certainly also grown. But a new study says another factor might be adding to Americans’ increased reliance on prescription drugs: advertising.

According to a new study by the National Bureau of Economic Research, both prescription drug advertising – and prescription drug use – rose significantly in many parts of the country after the passage of Medicare prescription drug coverage – Medicare Part D – in 2006. Researchers Abby Alpert, Darius Lakdawalla, and Neeraj Sood found that in areas with a larger share of senior citizens eligible for Part D, people saw an average of 72 more drug ads per year on TV, or one more ad every 5 days. This is turn was correlated with a 6 percent increase in the average number of prescriptions bought by non-elderly citizens.

The researchers also write that this increase is part of a broader long-term trend. Between 1990 and 2010, per-capita prescription drug use rose five-fold, while advertising for prescription medicines has grown nearly 30-fold since 1993. Data from Nielsen finds that drug companies spent $3.2 billion on TV ads in 2014 and were the nation’s third-largest buyers of airtime, after car companies and fast food restaurants. According to the NBER study, this means an average of 80 drug ads per hour are aired on American TV.

The rise in prescription drug use isn’t necessarily all negative. Much of the increase in drug-taking is for chronic conditions such as diabetes, high cholesterol and high blood pressure, which the CDC finds are actually under-treated conditions. For example, the CDC estimates that 73.5 million adults – or nearly 1 in 3 Americans – have high levels of the “bad” cholesterol linked to heart disease, but that only 48 percent are getting treatment. And of the 17.7 million adults diagnosed with diabetes in, 3.1 million – or close to 15 percent – are taking no medication at all.

Drug advertising may have benefits, the NBER researchers write, “if it educates patients about available treatments, encourages individuals to seek care for under-diagnosed conditions, and improves communication between patients and physicians.” Seeing ads on TV may also prompt people with prescriptions to do a better job of taking the medicines they need more regularly.

On the other hand, the researchers also say, ads may also lead to unnecessary treatments and expensive spending, particularly if patients insist on expensive brand-name medications over generics. What the research doesn’t yet make clear, the study says, if the impact of drug advertising is “to inform or to persuade.”

What is clear, however, is this: Americans’ medicine cabinets will continue to become increasingly full.