A sample of 50 adult admissions to an acute psychiatric service was studied by means of interviews with the patients and their family members for information concerning the onset or exacerbation of the current illness. Patients with organic brain disease were excluded, but the patients were otherwise unselected as to diagnosis. For 45 of the patients there was a reported loss of a highly valued source of gratification (object loss) and an emotional reaction of defeat ("giving up") in the time period immediately preceding the onset of the symptoms which led to their hospitalization. The actual or threatened event which led to feelings of unresolvable loss was reported as a "last straw" type of event by a third of the patients. The implication of these exploratory findings for a general hypothesis of disease onset is discussed.