One of the most important questions of our previous common volumes about affective, schizoaffective, and schizophrenic disorders was the question of what connects and what separates psychotic disorders (Marneros and Tsuang, Schizo affective Psychoses, Springer-Verlag, 1986; Marneros and Tsuang Affective and Schizoaffective Disorders, Springer-Verlag, 1990; Marneros, Andreasen, and Tsuang, Negative and Positive Schizophrenia, Springer-Verlag 1993). The boundaries between various psychotic disorders are not always clearly defined. Some groups of psychotic disorders, such as schizoaffective disorders and all the other "atypical" psychoses, occupy a position between "typical" mental disorders, such as schizophrenia, and affective disorders. The question is: Do psychotic disorders form a continuum, or are they, despite their unclear boundaries, distinct entities? On what basis should we assume there is a continuity of psychotic disorders? Solely symptomatology? Or perhaps also a continuity in genetic predispositions? Or in biological, pharmacological, and other dimensions? Is the old idea of "Einheitspsychose" (unitary psychosis) really always wrong? The contributions contained in this new volume cannot provide a definite answer to the above questions. But they try to describe some relevant aspects of the problem, and to give some partial answers. Halle-Wittenberg, Germany A. MARNEROS Brockton, USA M. T. TSUANG Iowa, USA N. C. ANDREASEN October 1994 Contents Part I Psychotic Continuum: An Introduction A. MARNEROS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Psychotic Continuum or Distinct Entities: Perspectives from Psychopathology CH. MUNDT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Psychotic Continuum Under Longitudinal Considerations A. MARNEROS, A. ROHDE, and A. DEISTER. . . . . . . . . . . . . . . . . . . . . . . . . . 17 Psychotic Continuum or Distinct Entities: Perspective from Psychopharmacology H. Y. MELTZER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The positive versus negative distinction of schizophrenic disorders has pro- moted ongoing research. Phenomenology, psychopathology, biology, genet- ics, pharmacological and nonpharmacological treatment, psychosocial and longitudinal research: all have found a new focus of interest. This volume attempts to provide an unbiased picture of the status of American and Eu- ropean knowledge regarding the positive/negative distinction. Researchers from North America and Europe describe the relation of modern concepts of positive and negative symptomatology to the original models of Rey- nolds and Jackson. Integrating phenomenological, genetic, and biological factors, the authors depict current methods of assessing positive and nega- tive symptomatology, differentiating between primary and secondary symp- tomatology, and using pharmacological and nonpharmacological treatment. The stability of positive and negative symptoms over time and evidence for the occurrence of separate positive and negative episodes over a long-term course of schizophrenia are extensively discussed in terms of their implica- tions on the positive/negative construct. The relevance of the positive/nega- tive dichotomy to child and adolescent schizophrenia is also debated. The main aim of this book is not to advocate a single concept and present only arguments supporting it, but to discuss important controversies. Prob- lems concerning a concept cannot be solved by ignoring them. However, unanswered questions may be resolved through discussion, debate, and con- structive compromise.