CLINICAL HANDBOOK OF SCHIZOPHRENIA

102 I. CORE SCIENCE AND BACKGROUND INFORMATIONONSET, PRODROMAL STAGE, AND FIRST PSYCHOTIC EPISODEKraepelin (1896) first described minor changes in mood, which may be recurrent or persistfor weeks, months or even for years as the only premonitory signs of an imminent mentaldisorder. Subsequent research has supported his observation. In about 75% of cases, schizophreniaonset occurs with slowly mounting depressive and negative symptoms that involveincreasing functional impairment and cognitive dysfunction. Less than 10% of cases startwith positive symptoms only. Reports on the duration of the prepsychotic prodromal stagevary widely. Because of differences in study designs and nonrepresentative populations,mean values range from a few months to 9 years. In a population-based sample of 232 firstepisodecases of schizophrenia assessed by the Interview for the Retrospective Assessment ofthe Onset and Course of Schizophrenia (IRAOS), 18% of patients had an acute type of onset(1 month from onset to first admission), 15% had a subacute onset (1 month to 1 year), andthe majority, 68%, had a chronic early illness course of more than 1 year before first admission.The mean duration of the prepsychotic prodromal stage was 4.8 years, with a medianof 2.3 years, indicating that shorter durations predominated (Häfner, Löffler, Maurer,Hambrecht, & an der Heiden, 1999).The onset of psychotic symptoms, which marks the beginning of a psychotic episode,is easier to assess. The duration of untreated psychosis (DUP)—in most studies about 1year—and the duration of untreated illness(DUI)—from first symptom to first contact—depend on help-seeking behavior and the availability of appropriate treatment. InNorway a program for promoting public awareness, including information toward thegeneral public, health services, and schools, managed to reduce DUP from 2.5 to 0.5years (Johannessen et al., 2001).The illness course preceding first contact can be studied in a state uninfluenced byantipsychotic or antidepressive medications. Table 11.1 shows the period prevalence andranks of the 10 most frequent symptoms of schizophrenia spectrum disorder and severeunipolar depression from onset to first admission in samples individually matched by ageand sex, and in “healthy” controls from the population of the study area. The two diseasegroups differ significantly from healthy controls at this early stage.Table 11.1 also shows a high degree of similarity at the prepsychotic stage betweenthe symptoms of schizophrenia and severe depression. This suggests that the first episodein these disorders is frequently preceded by a common prodromal syndrome comprisingdepressive and negative symptoms, and increasing functional impairment. Only a smallfraction of depressive and negative syndromes go on to develop psychotic symptoms or afull-blown psychosis.PSYCHOTIC AND DEPRESSIVE SYMPTOMS AS RISK FACTORSAND SYMPTOM DIMENSIONS OF PSYCHOSISChildren and adults with single psychotic symptoms without psychotic illness are at anincreased risk for developing psychosis. An increase in depressive symptoms or anxiety inearly adulthood also increases the risk for developing psychosis in the following years,whereas a decrease in anxiety and depression reduces that risk. Only a small proportionof patients with a schizophrenia spectrum disorder (e.g., 17% in the Age BeginningCourse study; Häfner et al., 1999) do not experience any depressive episodes before firstcontact. Most of these patients have negative symptoms, particularly affective blunting.More depressive symptoms at the prodromal stage predict more psychotic relapses. Themean prevalence of depressive symptoms in a psychotic episode ranges from 60 to 80%.