Focusing on child actors in The Walking Dead and other similar series / horror movies, where they take part in or see brutal activities (for example zombies).

I was wondering how child actors, such as Chandler Riggs in Season 1 of The Walking Dead, are allowed to be cast for and work in a series that they are legally too young to even watch. For example, Riggs was only 11 years old in Season 1 and was allowed to see other actors dressed as zombies, in addition to portrayals of zombies being shot or stabbed in the head, and subsequent guts / brains pouring out.

I understand that working on a set is no way near as ‘scary’ as the final edited piece portrays, but still to some degree these child actors are subject to seeing horrifying sights (of zombies, blood, guts, etc.) through the works of makeup artists and the likes. I mean the child (Riggs) was even given a replica gun! In addition to hearing and being allowed to swear (though I appreciate this doesn’t touch the scope of haunting sights).

Are the studios (AMC, for example) required to provide therapy to child actors who are subject to sights like this? For example in cases where sights of other actors in zombie makeup may trigger nightmares to such young actors (they may conciously be aware the ‘zombies’ aren’t real, but these child actors can’t control their dreams!).

I’m just curious about this, and can’t seem to find any directly similar questions out there.

Thanks in advance for any input from those that might have any knowledge about how studios are allowed to hire young actors for series like this!