I don't have the figures but say it's 0.01 percent of users are affected thusly. Sounds like a small, acceptable number and therefore, the drugs are released to market.
When the user population becomes large (enormous) that 0.01 % becomes a population and not a point.
When I started Paxil my brain suddenly told me to throw myself from a moving vehicle. The thought lasted for 1-2 months and occurred whenever I was in a car. Luckily that went away and now 95% of my anxiety is gone. I could only imagine if it triggered full blown schizophrenia. Also throw in the fact that an adult has much higher impulse control than a teen.