He wears black eyeliner and has chipped black polish on his nails and is currently lying in bed in a hotel room in Florida, having not yet got up although it is lunchtime.
The rest of the band are also asleep and scattered around the hotel - the shy singer, Patrick Stump, 21, the vegan drummer, Andy Hurley, 25, and the hyperactive guitarist, Joe Trohman, 21.
He withdrew from the rest of the band, only appearing to hand them his lyrics. Mom's [a school administrator] in the kitchen baking stuff, and dad's [a lawyer] off at work.
He is also a pop-punk entrepreneur, pushing Fall Out Boy unashamedly towards media brand, rather than pop band."My inspiration and my ideas don't begin and end at the beginning and the ending of a song.It is too limiting." It is no wonder that the singer, Stump, said of Wentz: "It scares me sometimes, watching him.He has admitted to a fascination with the suicides of Elliott Smith and Joy Division's Ian Curtis.But there is nothing fake about this dark period of his life, just stark honesty. The problem is I can get addicted to that feeling that you get from writing a song that can get unhealthy because you are relying on it." He does therapy even when he is on tour.In the Best Buy parking lot in Chicago, full of pain - "my head was racing with self doubt and negative thoughts" - he swallowed a handful of Ativan anxiety pills in an act that he calls "hypermedicating".He recalls: "I just wanted to have my head shut up."We are just ordinary boys in an extraordinary position," says Wentz. If there is any revolution we are inspiring it is that we have taken our own fate into our own hands.We are total control freaks." So much so that Wentz has created a record label, Decaydance Records (notable signings are Panic!He says the depression wasn't caused by any particular trauma in his childhood, which was "pretty mundane - the mundane and the ordinary can be very depressing. "It helps just to be able to give what you are thinking out.Keeping it in your own head is not always the best thing.