Perrie Edwards said about the track "When we were writing that, we were thinking about how music takes you over and gets inside of you," she said. "It's so good that you can't help but move. It makes you go crazy when you hear that song. It turns a bit creepier and creepier. We had those effects over "Welcome to the madhouse". It ends the album well!"
Jesy recalled to Artist Direct- "We were in the studio, and they played us this really unusual and funky beat. We decided to make a song about how music can take you over and make you crazy."
Popdust writer Andrew Unterberger stated: "So “Madness” is about how Little Mix’s music is so intoxicating and maddeningly catchy that it’s actually driven them to outright insanity, and they’re pretty cool with that? Makes sense, we guess. You can’t say that they don’t follow through with the analogy, though, down to the creepy Vincent Price-esque laughter that pops up throughout the song, and the extremely silly “Men in white coats, coats” bridge. If there was a music video for this song, it’d probably look like a cross between N’ Sync’s “Thinking of You (I Drive Myself Crazy)” and Backstreet Boys’ “Everybody (Backstreet’s Back),” and that certainly sounds like fun.
As for the actual lunacy of the song, it’s not quite on the level of Rihanna’s similarly-titled intro jam, but it’s frenetic enough to come off as at least mildly nutty, which makes for a good time. We’d certainly rather the regular edition of DNA close with a song like this than with yet another mid-tempo ballad, anyway." 
Little Mix performed "Madhouse" as a part of their DNA Tour in 2013.
The song was produced by Rufio Sandilands and Rocky Morris under the name of Pegasus. Sandilands and Morris were members of the English pop rock band Palladium who had a minor hit in 2007 with the song "High 5." Jesy recalled to Artist Direct- "We were in the studio, and they played us this really unusual and funky beat. We decided to make a song about how music can take you over and make you crazy."
- Little Mix - Writing
- Ian James - Writing
- Rufio Sandilands - Writing
- Rocky Moris - Writing
- Pegasus - Writing, Production
Click here to listen to it on Deezer