ABSTRACT
The differentiation of major depression from bipolar depression is the differentiation of impaired movement from disturbed thought. Flor-Henry [1] concluded that the primary determinant of mood is ‘‘related to the brain systems that determine volitional motility and visuospatial processing’’. Kraepelin [2,3] determined from decades of observing thousands of affectively ill patients that the defining characteristic of the depressed phase of manic depressive illness is ‘‘Willeshinderung’’ or volitional inhibition. Bipolar depressives suffer from a decreased ability to assert their will and initiate instrumental activities. As a result, these patients present motor retardation that ranges over a spectrum of intensity from mild sluggishness to the profound inhibition of depressive catatonic stupor (a state that Kraepelin describes as only slightly different from manic stupor). Kraepelin asserted, as late as 1921 [4], that anergia and motor retardation from paralysis of will clearly differentiated bipolar depression from ‘‘apprehensive depression’’ [5], the most frequent presentation of ordinary depression, whether it occurs in a recurrent pattern or in a single episode. Ordinary depressives (major depressives
in modern parlance) manifest apprehension, ideas, and/or delusions of sin, anxiety, and motor agitation (mild in some subjects, frenetic in the severely ill, who often turn out to be in the geriatric population).
