Having been a student of technical subjects at Princeton (and then Stanford) in the 1960s, I was conversant with, and at least mildly excited by, the promise of nuclear fusion. I am also bipolar, and was amused by the fact that lithium, which has helped me immensely, seems also to help, may I say, “bipolar” fusion plasmas (cover story, June 10). Apparently, lithium is not enough to solve all the plasma instabilities. Other psychoactive drugs might be tried with even greater success!