DIMENSIONS AND SUBTYPES OF RECENT-ONSET SCHIZOPHRENIA - A LONGITUDINAL ANALYSIS

A sample of young patients with schizophrenia was studied in a longitu dinal design to investigate the stability of an earlier reported four- dimensional symptom model (positive symptoms, negative symptoms, disor ganization, and depression). Symptoms were measured in an acute phase soon after hospitalization, in a remitted stage 3 months later, and in a ''mixed'' phase 1 year after the second assessment. A different fac tor structure was found at each measurement, but a stable four-dimensi onal structure could be defined that closely resembled the factor stru cture of the first assessment. The symptom dimensions were uncorrelate d, except disorganization and depression. Whether meaningful subtypes could be defined using statistical criteria also was investigated. Wit h cluster analysis, four subtypes were defined that could be character ized as follows: rapid treatment responders, slower responders, and tw o relapse groups. Although some indication of the validity of these su btypes was found, it is concluded that there is a high risk of creatin g artificial boundaries with this approach.