I really can empathize. My DD (also very creative and a DYS) is younger but has already dealt with some depression -- an existential sadness that leaves her feeling despondent about the future and a lack of meaning. I try to counter this by exposing her to philosophy and poetry and examples of how she can make a positive difference in the world, but I expect as she grows (and especially when she hits puberty/ teenage hood) that she will struggle. One book I found really useful and insightful is James Webb's Searching for meaning. Have you read it? It might be worthwhile for you (or your son) to look at if you haven't run across it yet...
https://www.amazon.com/Searching-Me...r=8-1&keywords=james+webb+depression
