Dr. Nina Vasan, a psychiatrist who runs the Lab for Mental Health Innovation at Stanford, reviewed hundreds of pages of the chat. She said that, from a clinical perspective, it appeared that Mr. Brooks had “signs of a manic episode with psychotic features.”

The signs of mania, Dr. Vasan said, included the long hours he spent talking to ChatGPT, without eating or sleeping enough, and his “flight of ideas” — the grandiose delusions that his inventions would change the world.

That Mr. Brooks was using weed during this time was significant, Dr. Vasan said, because cannabis can cause psychosis. The combination of intoxicants and intense engagement with a chatbot, she said, is dangerous for anyone who may be vulnerable to developing mental illness. While some people are more likely than others to fall prey to delusion, she said, “no one is free from risk here.”

Mr. Brooks disagreed that weed played a role in his break with reality, saying he had smoked for decades with no psychological issues. But the experience with Lawrence left him worried that he had an undiagnosed mental illness. In July, he started seeing a therapist, who reassured him that he was not mentally ill. The therapist told us that he did not think that Mr. Brooks was psychotic or clinically delusional.

Thought this part was interesting to include, especially for them to refer to cannabis as weed without quotation marks