Feeling anxious or unfocused? Your doctor may soon prescribe a course of gaming. Many puzzle games claim to keep brains nimble, but medical gaming could help treat conditions from autism to Alzheimer’s. EVO, a video game in clinical trials, is designed to promote cognitive functioning through foreign world exploration. And Pear Therapeutics in Cambridge, Mass., hopes to improve drugs’ efficacy by matching them to complementary gaming experiences. With virtual reality around the corner, such interactive treatments are likely to grow.