Step-by-step explanation:
I think it's because earth's atmosphere is getting more polluted; causing humans to develop disorders like ADHD and more. Not only that, Birth rate is affected by our spouses; Inheriting the same diseases they had. Who knows, they might've smoked when they were young! Plus, when veterans return home, they've already developed PTD. Teens are most responsible for the rate to increase due to the fact that they are growing in developing mental illness rates. That, or teens are just ignorant.