Startup Cerebral climbed up on the easy Adderall prescription. He was its undoing.

Online mental-health startup Cerebral Inc. was just getting started in early 2020 when it discovered a potential problem with its business model.

The company was focused on treating people experiencing depression and anxiety, charging a monthly fee to look up a nurse practitioner online for prescription antidepressants. But according to documents reviewed by The Wall Street Journal and people familiar with the matter, patients canceled their subscriptions after only a few months, making it more difficult for the company to cover advertising and other costs.