Long-term trends of symptoms and disability in schizophrenia and related disorders

Background: Relatively few studies describe the long-term course of schizop hrenia in well-defined cohorts of patients assessed soon after the illness onset. The aim of this paper is to describe the overall trend of schizophre nia in a 16-year follow-up study of patients and to explore the predictive value of several variables measured at the time of inclusion in the study. The course of the disorder is described along both a 'clinical' and a 'soci al' dimension. Methods: The sample of 60 patients with a recent onset of a non-affective psychosis was first assessed in 1978-1980 as part of the stud y, coordinated by the WHO, on Reduction and Assessment of Psychiatric Disab ility. Data from the last follow-up are used to rate the overall trends of psychotic symptoms and of social disability. Based on a subdivision of the follow-up period into three sub-periods, the trend for the patients is rate d for each of the two dimensions as improvement, deterioration, and no chan ge or fluctuating. The associations of these trends with several predictor variables (age at onset, gender, martial status, education level, family hi story of mental illness, type of illness onset, personality assets) are exp lored by cross-tabulation (with calculation of the relative risk) and by a logistic regression model. Results: The predominant pattern for psychotic s ymptoms is improvement (55% of the subjects), while the predominant pattern for social disability is deterioration (45% of the subjects). A trend of i mprovement of psychotic symptoms correlated significantly with a negative f amily history of severe psychiatric disorder and with an acute type of illn ess onset. Only the first variable entered the logistic regression model. A trend of improvement of social disability correlated significantly with ge nder, marital status, presence of personality assets, and type of illness o nset. All of these predictors entered the logistic regression model, with t he exception of marital status; age at onset also entered the logistic regr ession. Conclusions: Psychotic symptoms and social disability are relativel y autonomous descriptors of the course of schizophrenia. A speculative hypo thesis is that symptom course is more closely related to innate factors, wh ile social disability is contingent upon the acquired level of personal and social competence at the time of illness onset. Future studies are needed to assess the effects of psychiatric interventions that could ameliorate th e long-term prognosis of social disability in patients with schizophrenia.