In the hope of discovering simple disease entities that could permit specific treatment, much effort is currently directed toward the operationalization of psychopathological syndromes. As a necessary supplement to these endeavors, the pathophysiological aspect is emphasized in this study. The nonspecificity of pathophysiological mechanisms with reference to psychiatric syndromes is illustrated using the example of inhibition of the orienting reaction in schizophrenia and depression. It is demonstrated that these mechanisms are meaningful for therapy despite their nosologic nonspecificity.