Over the past decade, there has been a noticeable shortage of prescription drugs containing controlled substances, such as narcotics and stimulants, causing difficulties for both patients and physicians. Doctors have to scramble to find alternatives and, sometimes, patients simply go without treatment. As it so happens, a new report finds the U.S. Drug Enforcement Agency has contributed to the problem.

How is this possible? Well, controlled substances are regulated by DEA, because of the potential for abuse and addiction. And to prevent diversion, the DEA sets quotas that limit the amount that can be produced. The DEA, however, has not effectively managed the quota process and this has contributed to product shortages, according to the U.S. Government Accountability Office.

“Each year, manufacturers apply to [the] DEA for quotas needed to make their drugs,” the GAO writes in its report. The “DEA, however, has not responded to [the drug makers] within the timeframes required by its regulations for any year from 2001 through 2014… Manufacturers who reported quota-related shortages cited late quota decisions as causing or exacerbating shortages of their drugs.”

For its part, the DEA disputed some of the findings and also argued that some of the problems stem from disagreements with the FDA, notably, that the two agencies have differing views on how to define prescription drug shortages.

Concerns about the DEA were raised three years ago by two U.S. Senators – Chuck Grassley (R-Iowa) and Sheldon Whitehouse (D-R.I.) – who wrote the GAO and asked the agency to conduct a study about the extent to which the DEA was contributing to shortages of controlled substances. At the time, there were a rising number of prescription drug shortages.