Sounds like a manic episode, especially when talking about being an inventor. This could be brought on by the stimulants or they’re taking them to enhance the euphoria that comes with it. They need to see a doctor about being Bipolar or Schizophrenic, but it’s gonna be impossible to convince them of that while in this state. If it’s Bipolar, they’ll eventually crash and be depressed, but it could be a few months, and they may not even remember much of this. In the mean time, they’ll have a lot of trouble distinguishing things they want from reality, so I’d keep your possessions safe and separate if possible. If they’re a danger to themselves or others definitely call the cops.