Telehealth startup Done, which prescribes ADHD medication like Adderall, is under investigation by the Drug Enforcement Administration, The Wall Street Journal reported.

The investigation is part of an ongoing crackdown on mental health companies using telemedicine to prescribe controlled substances, a category that includes stimulants like Adderall and addictive painkillers like OxyContin. The DEA is also investigating telehealth company Cerebral over its prescribing practices. That company announced it would stop prescribing drugs in that category in May.

Done told The Wall Street Journal that it hadn’t had any direct contact from the DEA and that it is committed to “complying with all applicable laws and regulations.”

Before the pandemic, startups like Cerebral and Done couldn’t exist — doctors had to see a patient in person in order to prescribe a controlled substance. But those rules were relaxed under the COVID-19 public health emergency, opening the door to these types of telehealth companies. They advertised heavily on platforms like TikTok and made it easy for people to get a diagnosis and medication for conditions like ADHD. Some clinicians working for the platforms say they made it too easy and that they felt pressure to prescribe medications.

It’s still very much up in the air whether or not pandemic-era telehealth rules will stay in place after the public health emergency ends. The latest move from the DEA, which is responsible for the regulations, shows that the agency is still scrutinizing the landscape.

That’s worrisome to some doctors. Even though the rules may have contributed to the overprescription of stimulant drugs like Adderall, they’ve also made it easier for doctors to distribute medications for opioid-use disorder — which are also controlled substances. Those doctors worry about their patients getting caught up in the backlash and losing a tool to treat addiction.

“It’s very easy for these things to kind of get grouped together in people’s minds and then also in policy,” Shoshana Aronowitz, a health services researcher at the University of Pennsylvania who provides substance-use disorder treatment in Philadelphia, told The Verge last month.