Former Cerebral CEO says investors pushed prescribing of stimulants and used him as a "scapegoat"

The former CEO and founder of online mental health care giant Cerebral sent a letter to the company Friday demanding access to "books and records" that he says could reveal whether the startup violated the law, setting the stage for a potential lawsuit.  Former Cerebral employees say company's practices put patients at risk: "It's chaotic. It's confusing. It could be extremely dangerous" Expert alarmed by mental health app Cerebral's speedy sessions and prescriber qualifications

Kyle Robertson was ousted from the company in May as scrutiny increased over Cerebral's prescribing of stimulants like Adderall, which is used to treat attention-deficit/hyperactivity disorder and is considered a controlled substance. Earlier this year, the Department of Justice launched an investigation of allegations it over-prescribed controlled substances.

In the letter obtained by CBS News, Robertson says he was pressured by the company's investors to "sell more stimulants" and believes his ouster was an effort to "scapegoat" him as these investigations arose.