The natural history of schizophrenia: a five-year follow-up study of outcome and prediction in a representative sample of schizophrenics

Abstract

Longitudinal studies of schizophrenia based on at least 70 subjects and a minimum five-year follow-up period are reviewed in respect of the requirements of adequate method. A cohort of 121, PSE-diagnosed, schizophrenic admissions from a defined population was identified. The sex-distribution of the subjects was almost equal. Forty per cent were first admissions; 65% of the men and 24% women were unmarried; the mean age of onset for men was 28.6 years, for women 33.2 years. Almost half (48%) were continuously employed (including house and child care) for 2 years prior to admissions. First rank symptoms of schizophrenia were present in 79% of the men and 86% of the women. Comprehensive, standardized assessments of clinical state and social function were made on discharge from hospital and at follow-up by home interview of patient and relative(s). Outcome was also assessed by duration and frequency of readmission and by duration of employment. First admissions were analysed separately from the whole cohort. There were 49 first admissions generating an incidence of 7.4 per 100,000 general population per annum. Sixty-nine per cent of men and 13% of women were unmarried. The mean age of admission for men was 30.8 years, women 40.3 years and the mean age of onset 30.7 and 38.6 respectively. After 5 years first rank symptoms were present in 46% of the males and 35% of the females. The proportion showing depressive symptoms fell from 39% at intake to 22% at five years. In terms of a combination of symptoms and readmissions there was a good outcome in 50% of men and 65% of women, a trend comparable to that found in the whole cohort. For the whole cohort a combination of the number of symptoms and admissions disclosed a good outcome for 48%. The mean total duration of readmissions during the five years for men was 76 weeks and for women 27 weeks. Depressive symptoms were present in 38% at intake and 21% after 5 years. An overall rating of social functioning at 5 years showed no more than mild impairment for 47% of men and 74% of women, although individual items were more impaired. However, 38% of the group showed no more than mild impairment in any aspect of social functioning rated. Clinical and social outcome were, in general, closely correlated. The difference in outcome between men and women and the relations between clinical and social outcome are discussed. By means of an application of measures of association between independent and dependent variables to the onset data the clinical and social categories of pathology and impairment at 5 years were forecast.(ABSTRACT TRUNCATED AT 400 WORDS)