“…Different factors were responsible for the development of RP in different psychiatric traditions since its inception in the work of Jaspers (1913Jaspers ( /1948. In Scandinavian countries, RP was readily accepted and further developed as a category encompassing emotional, confusional, and paranoid syndromes distinct from schizophrenia and bipolar disorder (Castagnini, 2010;Faergeman, 1963;Retterstøl, 1966;Schioldann, 2020;Strömgren, 1940;Wimmer, 1916), whereas in Continental (European) and British psychiatry, its diffusion was hindered by strong opposition to "psychogenesis" and controversies about the validity of reactive depression (Lewis, 1934(Lewis, , 1972Slater, 1964). Schneider's (1959 view that all psychoses have a "somatic" basis was also influential and contributed to causing the neglect of RP in modern psychiatric classifications (Gabriel, 1987;Strömgren, 1989).…”