Affective and schizophrenic disorders are not monolithic concepts. The idea of groups of disorders has proved to be useful. Today the concept of a spectrum of affective disorders and a spectrum of psychotic disorders is based on clinical and research findings. It has also been proposed that a kind of continuity exists between the two spectra. There are clinical bridges joining them, or perhaps some nosologic islands filling the gaps in-between. Possibly what is “in-between” represents a cross of the underlying dimensions of the two “voluminous” spectra, or a superposition of some of the contributory factors of one or that of the other.

Psyche is like Physis – Nature. She does not take any leaps, even when she is ill. Emil Kraepelin himself realized the indistinct boundaries of the dichotomy of the manic-depressive and schizophrenic psychoses he had proposed at the turn of the nineteenth century. He thought that it was only partially true. One can read it in his paper published in 1920: “Die Erscheinungsformen des Irreseins”, which means “The manifestation types of insanity”. Among other relevant observations, he noted:

Broad–narrow–broad: the circuitry of certainties and uncertainties

In the centuries between the great Greek founders of medicine and psychiatry, Hippocrates, Aretaeus of Cappadocia, Galenos of Pergamon or Soranos of Ephesos (see Longrigg, 1993; Marneros and Angst, 2000; Angst and Marneros, 2001) and the father of the modern psychiatric systematics, Emil Kraepelin, at the end of the nineteenth and the beginning of the twentieth century, physicians and psychiatrists described and allocated mental disorders according to broad criteria. Symptoms, which today in modern nomenclature are called “schizophrenic,” “affective,” “mood congruent” or “mood-incongruent,” were described as characteristics of the same disorder. Therefore, case reports published during this long historic period of more than 2400 years could, with the same strong arguments, be interpreted by modern psychiatrics as “pure schizophrenia,” or “pure affective disorder” or “typical schizoaffective.” At the end of the nineteenth century, Emil Kraepelin tried to clean the field, dichotomizing the so-called functional psychotic disorders into dementia praecox and manic-depressive illness (Kraepelin, 1896; 1899). The Kraepelinian dichotomy, which really was not very dichotomous, as Emil Kraepelin himself pointed out in 1920, received an epigonal strength by Kurt Schneider (1959) through the definition of “first-rank schizophrenic symptoms”: their existence confirms the diagnosis “schizophrenia” (provided that organic causal conditions can be ruled out). Kurt Schneider's ascetic strength completed in some way Karl Jaspers' hierarchical principle (1913).

Introduction

Brief and acute psychoses – as differentiated from schizophrenia and affective disorders – have long intrigued psychiatrists. Their nosological allocation has been a matter of debate. The World Health Organization (WHO) tried to solve this problem by creating the ICD-10 category F23: “acute and transient psychotic disorders” (ATPD). The ATPD is defined as a psychotic disorder of acute onset (within two weeks) and of limited duration (not longer than three months). For a diagnosis of ATPD, major affective disorders, organic disorders, and schizophrenia have to be ruled out. The creation of this category represented an attempt not only to define and operationalize such psychotic conditions, but also to integrate some national concepts such as the cycloid psychoses of German psychiatry, the bouffée délirante of French psychiatry, the psychogenic psychosis of Scandinavian psychiatry, the atypical psychosis of Japanese psychiatry and the remitting or good-prognosis schizophrenia of USA psychiatry into one single category (Marneros and Tsuang, 1986; Marneros et al., 2000; Pillmann et al., 2000; 2001; Marneros and Pillmann, 2004). The DSM-IV provides the category of brief psychotic disorder (BPD). A diagnosis of BPD requires the presence of delusions, hallucinations, disorganized speech, or grossly disorganized or catatonic behavior, with a duration of at least one day but less than one month and eventual full return to premorbid functioning.

Introduction

The term “schizoaffective psychosis” was first introduced by Kasanin (1933) when he described a group of patients with good premorbid functioning who developed acute psychoses with a mixture of psychotic and affective symptoms, but fully recovered after a few months. While Kasanin is credited with introducing the term, it is defined differently now. Schizoaffective disorder is a complex illness whose definition has changed significantly over time. Despite the continued attempts to better define and classify schizoaffective disorder, much controversy and conflicting results remain. Unfortunately, schizoaffective disorders have been poorly investigated. Kahlbaum (1863) is usually considered the first psychiatrist in modern times to describe schizoaffective disorders as a separate group (Angst and Marneros, 2001). As Tsuang and Simpson (1984) reported, empirical findings are often contradictory and have at times supported the idea that schizoaffective disorder is (a) a variant of schizophrenia; (b) a variant of affective disorder; (c) a different and heterogeneous diagnostic group.

Regarding classification systems, in DSM-II schizoaffective disorder was included in the group of schizophrenic disorders, although some studies with controversial results were published (Procci, 1976; Harrow, 1984). While in DSM-III schizoaffective disorders had only the state of a remnant category, in DSM-III-R schizoaffective disorders were extended to a “true” entity with specific diagnostic criteria (Jäger et al., 2004).