Because it's a complicated brain thing that affects too few people in a way that is not physically harmful, so there's no financial incentive for large corporations to invest the hundreds of millions it would require to find a treatment. If there even is a treatment. Maybe it'll happen someday, but there are a lot of other maladies that also have no treatment. I have friends with celiac who can't eat gluten. We can't fix that either. 🤷🏻‍♂️