Nervous System is the third extended play and major-label debut by American singer and songwriter Julia Michaels, released by Republic Records on July 28, 2017.

Most of the tracks on the EP were composed by Michaels and her frequent writing partner, Justin Tranter, as well as the songs producers, Benny Blanco, Stargate and Mattman & Robin.

From 2013 to 2016, Julia Michaels became well known for writing songs for Selena Gomez, Justin Bieber, Demi Lovato, Britney Spears, Gwen Stefani and several other artists.

The second single of the EP, "Uh Huh", is described by Mike Wass of Idolator as "brighter, bolder and more instant" than "Issues", as well labeling the chorus as "obscenely catchy".

[6] The last track, "Don't Wanna Think", is the only song on the record written entirely by Michaels and is a piano ballad that follows a basic sequence of F–C–Am–F as its chord progression.

"[8] Chris Willman of Variety wrote that the EP "reveals Michaels as a gifted enough singer and confession-inclined enough songwriter that leaving out the middleman was definitely the way to go."