Typical phases of student experience/motivation in academic education (e.g. PhD)

I have heard and experienced anecdotally that students often go through various phases in academic education, be it undergraduate or postgraduate, starting with enthusiasm and excitement, then running into a dip, before climbing out again and feeling more motivated, although later fatigue may set in. This can occur over the course of a single year, but also over the course of a degree (see, for instance, 5 Phases of PhD Motivation Explained). There may be some connection with the stages of culture shock, and for some students traditional culture shock might be compounded with the aforementioned phases.

Have studies been carried out on the phases students seem to go through and are they as widespread, even universal, as experience would suggest? References to particular studies would be appreciated. I would also be interested in references to effective coping strategies for recovering from the first serious dip, which may otherwise derail a student's studies.