Studying chess makes me feel cognitively healthier in every way, with the possible exception of my sleep schedule. I don’t know if I have cause and effect reversed - maybe I can only do it when I’m feeling okay - but I feel like it builds the habit of stopping and thinking when I feel confused or overwhelmed, a position chess puts me in frequently. Calculating approaches to a complex position is good memory training, as well as teaching me that I am not powerless whenever things look difficult.