The Drug Enforcement Administration told makers of medication for attention-deficit hyperactivity disorder that it was concerned that “aggressive marketing practices” by companies including telehealth providers could be driving excessive prescriptions, according to a letter from the agency.

While the letter doesn’t cite specific companies, it reflects the DEA’s concerns about marketing efforts for ADHD treatment by telehealth companies such as Cerebral Inc. and Done Global Inc., whose prescribing practices the agency has been investigating. The DEA said in December that it wouldn’t allow any increase in 2023 production of pharmaceutical ingredients that go into Adderall and other stimulants used to treat ADHD. The letter, reviewed by The Wall Street Journal, was sent to drugmakers over the summer but hasn’t previously been reported.