According to an article from www.Insidehihered.com (April 2008), only 57%** of PhD candidates complete their degrees. If you have lost the drive to complete your PhD or wondering why you bothered to pursue this career direction in the first place, you are not alone: many others have had similar thoughts.
If you decide to leave, the question is what can you do with all this education to which you cannot attach a degree designation?
A registered PhD student can claim candidacy when all her degree requirements except the thesis have been completed. This usually includes having completed your comprehensives (comps) and the dissertation proposal. To officially be considered a “candidate” at the University of Toronto, a candidacy recommendation form must be sent to SGS by the graduate student's unit or program. “Candidacy Achieved” will appear on her transcript as a result. Only a registered student can submit this request.
Unregistered students cannot officially declare themselves "candidate." However, there’s probably no harm in referencing your status on a resume as "candidate" or “ABD” (all but the dissertation), as long as you have, in fact, reached this point in your studies. While it is the practice in some UK and US institutions to award a Masters degree for an incomplete (or failed) PhD, this is not the practice in most Canadian schools and not at the University of Toronto, where each degree is considered a separate program of study.
** For more information visit: http://www.insidehighered.com/news/2008/04/01/graduate