“…On the basis of clinical observation, psychiatrists have tended to assume that an acute onset of mental illness is a favorable prognostic sign, and insidious onset is an unfavorable sign [6,8,9]. Uncontrolled clinical studies have provided tentative evidence in favor of this point of view [1,3,4,5,10,11]. Bellak's review of the literature on dementia praecox [2, pp.…”