I always wondered about scenes in movies or tv shows that show a child dealing with some sort of a disturbing, gruesome or difficult situation. I'm talking about how the child actors are dealt with and how the hard scenes they have to act in are explained to them.
For example, in some movies (mostly horror/thriller genre) we see a child as a antagonist: a villain with a twisted mind, a killer or abuser. Some of this type of movies are really disturbing and hardcore, with explicit content (blood, vulgar language etc.). Or movies where said child's parents are killed, the child is abused/beaten/assaulted in any other way.
How is it explained to child actors that this is just "pretend"? Of course this applies to really young actors, I guess that teenagers or 9/10 year olds are fully aware that the movie is just a movie and it's not real. Same goes for little, little kids like infants - they probably don't even know what's really happening.
Is there some sort of a psychologist or counselor involved in the movie that talks to the child actors and helps them go through the often really though content they have to act through?
Or maybe those scenes are shot or edited in a specific way that the child actor is not really involved in a difficult scene but it is then edited and added to the final piece in post-production.