Fulminant psychosis is generally recognized in clinical practice, whereas inconspicuous borderline phenomena often cause much more difficulty for the clinician. In the borderland of psychosis we meet a number of phenomena designated as “near-psychotic” or “psychotic-like.” Some of these have clear state or occurrent character, others a more habitual or dispositional character (Parnas, Licht & Bovet, 2005a). The definition of “near-psychotic” is directly dependent on the notion of psychosis. In a clinical context, psychosis often refers to an explicit dislocation of reflective propositional “theoretical rationality” (Parnas, Nordgaard & Varga, 2010; see also Parnas, Chapter 2) presenting as delusions. For practical clinical purposes, near-psychotic symptoms (also known as attenuated psychotic symptoms or psychosis-like experiences, or PLEs) may be seen as phenomena in which the psychotic conviction is less intense and which are formed or elaborated to a lesser extent, or which can be seen as transitory psychotic symptoms.