Would social services do a drug test if asked.?

my nephew is ten years old. his parents just went threw a divorce and he got a little rebellious. his parents are nuts! they have him on anti depressant that mack him sick, anxiety pills that make him Dizzy and now there is a huge fight where there going to put him in a mental institution... what can we do? i am positive his parents are on serious drugs- weather coke which i know they have been before or something worse., could we get them tested to possibly get custody of this child.