CLINICAL HANDBOOK OF SCHIZOPHRENIA

108 I. CORE SCIENCE AND BACKGROUND INFORMATIONMarengo and colleagues (2000) included the depression factor in addition to thethree other factors and did follow-ups at 2.0, 4.5, 7.5, and 10.0 years after first admission.In agreement with more recent studies, the authors concluded that “depression constitutedan independent and stable dimension of schizophrenia” (p. 61) over the entirecourse of the illness. These findings underscore the heterogeneity of the symptom dimensionssubsumed under the disease concept of schizophrenia.Because there is clear overlap between the clinically defined depressive and the negativesyndrome, an der Heiden and colleagues (2005) studied a depressive core syndrome(depressive mood, lack of self-confidence, feelings of guilt, suicidal ideation) and a maniccore syndrome (elated mood, reduced need for sleep, pressure of speech, hyperactivity,flight of ideas) over an illness course of 11.3 years in a sample of 107 patients withschizophrenia. They found a modal rate of 35% for the depressive core syndrome and of6–7% for the manic syndrome, and a high degree of stability for both syndromes over thelong-term. Figure 11.3, based on IRAOS data for 134 months, validated at seven crosssections with the Present State Examination (PSE) interview, illustrates the remarkablestability of—and the lack of a trend in—the prevalence rates for depression and the maniccore syndrome. Months spent with depressive symptoms are the most frequent (47.1),compared to months of psychotic symptoms (13.7). Purely depressive relapse episodesoccur at a frequency of about 1 to 5 compared with psychotic relapses. This means thatdepressive symptoms increase with the emerging disorder and occur as an integral part ofpsychotic episodes at all stages of the course of schizophrenia. So far depression has notbeen given the attention it deserves in the treatment of schizophrenia, despite its great importancefor patients’ subjective quality of life, coping, and increased risk for suicide.The frequency of psychotic relapses is difficult estimate, because their number variesdepending on the patients’ living environments and can be triggered by stressful lifeevents and stressful home environments, and because precise information on antipsychotictreatment is not available. In the population-based ABC Schizophrenia Study (ander Heiden et al., 2005) covering an 11.3-year illness course under treatment, the fre-FIGURE 11.2. Correlation within and between syndrome ratings at six points in time over 5 years.The factors were tested by explorative orthogonal factor analysis at each of the five follow-ups;ABC subsample of 115 first-illness episodes. Data from Löffler and Häfner (1999).