Only 30-55% of depressed patients respond to sleep deprivation, and responders cannot be reliably predicted.

“not all patients respond to sleep deprivation in fact if you look at the data it's somewhere between 30 to 55% of patients will be responders to sleep depravation the other proportion of those patients don't respond or if anything get worse when you sleep deprive them and then the question is well how would you know and right now and there have been some brain Imaging studies some pet studies done way back at UC irine U and other locations where they were trying to say is there something about the metabolic activity of your brain that can predict if you're a responder or not”