When you start to see random words capitalized, like Grievers or Gladers or Scorch or Cranks or Maze—the list goes on and on—then you're probably reading some kind of fiction novel. Then, when you realize that everything is sort of normal but messed up in a weird sort of way—like there may no be no witches or wizards or time travel, but things are just generally deserted and scary and desolate—then you can be fairly sure you're reading some dystopian lit.
If the book's about kids, then you can be almost 100% percent sure it's YA dystopian lit.
This novel follows the dystopian path pretty much by the Dystopia for Dummies book: it's set in a futuristic but not too distant time period; the boys are in a location that we can recognize (the Scorch is most likely in Mexico); and some kind of disease or catastrophe has plagued the earth. In this case, we're talking about the Flare.
In most dystopias, a bomb has gone off, or some kind of disease is wiping out civilization, or the end of the world has happened or is about to happen. There's always some kind of turmoil going on, and this turmoil isn't just black magic—it's realistic.
Sure, there can be monsters and flying saucers and random transportation devices in a dystopia; it just needs to seem realistic—because if it doesn't, then probably you're reading a fantasy novel.