Navajo boy in Brother's Little Helper

An old episode of The Simpsons has a Native reference I hadn't noticed before:

Brother's Little Helper"Brother's Little Helper" is the second episode of the 11th season of The Simpsons. It aired on October 3, 1999. The title refers to an early Rolling Stones song, titled "Mother's Little Helper," which is about stressed housewives abusing prescription drugs.

Plot

Principal Skinner introduces a fire safety skit to the students. When Ned Flanders catches on fire, the fire department tries to extinguish him. It doesn't work because Bart is pulling a prank with the fire hose, though water crashing out of the gym saves Flanders anyway. Skinner has Homer and Marge come to the school, where they learn Bart has been diagnosed with Attention Deficit Disorder (ADD). Principal Skinner tells Marge and Homer that Bart must take a radical, untested new behavioral medicine called Focusyn or Skinner will have to expel him.

After several failed attempts by Homer (including naming several celebrities on drugs, such as Motley Crue's Tommy Lee, sitcom actress Brett Butler, and actor/comedian Andy Dick, and offering Bart taffy laced with several Focusyn pills sticking out), Marge convinces Bart to take the medication. His behavior immediately improves. He begins paying attention in school and being respectful to his parents (even tutoring a Navajo boy in his spare time). However, side effects soon occur, as Bart becomes paranoid that Major League Baseball is spying on the town using satellites. The doctors recommend that Bart go off Focusyn, but he refuses. Before anyone can stop him, he swallows several handfuls of Focusyn and runs away.Comment:  In a brief scene, Bart asks a Navajo boy the meaning of the "Humpty Dumpty" nursery rhyme. The boy comes up with a correct answer.

For more on the subject, see Indians in The Simpsons.