(Bloomberg) -- Novartis AG, the second-biggest maker of generic Adderall in the US, is reporting new supply issues of the attention-deficit/hyperactivity disorder medicine as shortages grow, leaving patients scrambling. 

Novartis’s Sandoz unit, previously reported as having supply issues with only the extended-release medication, is now also having challenges with the immediate-release version, according to the University of Utah’s drug information service, which tracks drug shortages. The company has shortages of two dosages of generic immediate-release Adderall, according to an update from the university.

Millions of Americans depend on the medication to treat ADHD. Without the pills, it can be difficult for people with the condition to concentrate and focus. The drugs have been in short supply at independent and chain pharmacies around the country, leaving patients struggling to fill their prescriptions. It’s an added challenge for people with ADHD who often rely on their medication to help them complete basic tasks - like doing laundry or filling prescriptions.

Seven pharmaceutical companies in total now have shortages of generic immediate-release or extended-release Adderall, according to the update of the service’s website Thursday. Last month, six companies had the drug in short supply, according to the university’s updates.

Patients on the drug can take either a once-daily extended release pill or a shorter-acting immediate-release formulation, with some taking a combination of the two.

Switzerland-base Novartis, which the university did not previously report as having supply issues with the immediate-release medication, now has shortages of two dosages of generic immediate-release Adderall. They’re the second-largest supplier of generic immediate-release Adderall in the US, accounting for 14.5% of prescriptions dispensed so far this year, according to data from Symphony Health. 

The University of Utah’s update now shows Camber Pharmaceuticals Inc. and Sun Pharmaceutical Industries Ltd. reporting shortages of generic extended-release Adderall. Lannett Co. previously had short supplies of a dose of generic extended-release Adderall. The company is no longer reporting that shortage, according to the update.

Teva Pharmaceutical Industries Ltd., which sells the most Adderall in the US of any company, has had trouble with its supply of the medication since the summer. According to the University of Utah update, Teva should have more supply of the 10mg, 20mg, and 30mg generic immediate-release Adderall this month and of the 15mg pills next month. Teva makes both branded and generic Adderall. 

Adderall has been in short supply for years. The US Food and Drug Administration reported a shortage from September 2019 through May 2022, but is not currently reporting any issues. 

Demand for the drug is at an all-time high, driven by increased awareness of and diagnoses of ADHD. Since the start of the pandemic, some online companies have made it easier for people to get ADHD diagnosis and Adderall prescriptions through telehealth. Two of those startups, Cerebral Inc. and Done, are under federal scrutiny. 

Camber, Sandoz, Sun, Teva, and the FDA did not immediately respond to requests for comment.

©2022 Bloomberg L.P.