This should be at the sole discretion of the parents. Maybe if this was an elective in high school or college, but this has no place in children's classrooms considering this subject, to many, is still considered a mental illness.
A child's mind is like a sponge. Its still soaking in all of the other new content they come into contact with everyday. They aren't mentally mature enough to handle such a complex subject. Anybody that thinks a kid can digest information such as this is severely mistaken. Children have enough to contend with everyday thanks to us. Don't add this to the pile.