Kraepelin and Blueler suggested that subtle manifestations of schizophrenia are present in some persons for many years before formal diagnosis and that the severity of these is associated with outcomes in schizophrenia. Empirical support for this hypothesis comes primarily from small samples using retrospectively collected data. We tested this hypothesis, for the first time, using a population-based cohort. The Israeli Draft Board Registry, which contains measures of intellectual and behavioral functioning for the unselected population of 17-year-olds, was merged with the National Psychiatric Hospitalization Case Registry that contains data on all psychiatric hospitalizations. The database was used to identify adolescents assessed by the draft board at least 1 year prior to their first hospitalization for schizophrenia (n=996) or affective disorder (n=335). Poorer social functioning and organizational ability prior to first admission were associated with more days per year in the hospital for the male schizophrenia group. There were no significant correlations between days per year in the hospital and any of the behavioral functioning measures for the affective group. Among females the higher the previous level of intellectual functioning the fewer the days per year in the hospital in both the schizophrenia group and affective groups. For males no such correlations were evident. The comparisons between patients who had one as opposed to more than one admission found that in both diagnostic groups female patients with one admission had higher pre-first hospitalization intellectual functioning. Gender and disease specific premorbid deficits have may have differential prognostic value for outcomes in schizophrenia and affective disorders.
- Premorbid functioning