The US Defense Advanced Research Projects Agency (DARPA) is developing a type of stimulant without the attendant side-effects of regular stimulants such as anxiety, irritability, or euphoria.

The ingested stimulants are activated through the contact of certain types of light sent non-invasively through a device.

They target certain brain circuits “responsible for executive function, working memory, and decision making, while avoiding off-target effects,” DARPA explained. DARPA Developing Stimulant to Keep Warfighters Alert Without Side Effects (thedefensepost.com)