(NewsNation) — A growing shortage of Adderall is making it hard for people to find the prescription drug, which is taken to treat attention deficit hyperactivity disorder, or ADHD.

More than six in 10 pharmacies are reporting difficulties obtaining the medication for patients, a survey from the National Community Pharmacists Association found.

According to the Food and Drug Administration, logistical challenges and worker shortages may be contributing to the problem.

The most recent companies experiencing limited supplies of generic extended-release Adderall are Lannett Co. and Par Pharmaceuticals, USA TODAY reported. The newspaper said nine companies supply branded and generic Adderall in the nation.

Previously, there was a nationwide shortage of Adderall the FDA reported from September 2019 through May 2022 because of increased demand for the drug, USA TODAY said, although the administration is not currently reporting one.

“Drug shortages, particularly generic drug shortages, are not a new phenomenon, but a common and increasing issue in the United States of America, where approximately 90% of filled prescriptions are generic drugs,” Dr. James Besante, an addiction medicine specialist, said on NewsNation’s “Morning in America.” “Drug shortages are thought to be a result of a combination of factors … supply chain issues, natural disasters, regulatory hurdles.”

Because of the low profitability of producing generic drugs, manufacturers routinely decide to stop production, Besante said. Even one company halting production can dramatically impact already fragile supply chains.

For those who don’t have access to Adderall, Besante said there are some alternatives.

“Talk to your pediatrician, talk to psychopharmacologists, your psychiatrist or (primary care physician),” Besante suggested. “There are several different alternatives to treat ADHD.”

Drug shortages will continue to be an issue as long as the nation relies heavily on the production of generic manufactured drugs, Besante said, which are used to offset the exorbitant amount Americans pay for name-brand drugs.

“Americans pay drug prices two to three times higher than other developed nations,” he added.

As a practicing physician, Besante said he gets an email from his hospital or pharmacies about shortages of all kinds of medications.

“It’s a very dynamic issue that’s always changing,” he said. “When this happens with a controlled substance like Adderall, it’s very newsworthy, but it’s a consistent issue here in the United States of America.”