Some authors have conceptualized depression as a "depletion syndrome" because of the prominence of fatigability; they postulate that the patient exhausts his available energy during the period prior to the onset of the depression and that the depressed state represents a kind of hibernation, during which the patient gradually builds up a new story of energy.

Depression: Clinical, Experimental, and Theoretical Aspects (ed. University of Pennsylvania Press, 1967) - ISBN: 9780812210323