Has the prevalence, clinical presentation and social functioning of schizophrenia changed over the last 25Â years? Nithsdale schizophrenia survey revisited

The clinical manifestation of schizophrenia appears to have changed over the last 25 years, within this geographically-defined area, the prevalence of negative symptoms having decreased, and positive symptoms seem to have increased. The level of social functioning does not appear to have changed over the last 25 years.