Refining the diagnosis of schizophreniform disorder.

Schizophreniform disorder, a potentially useful construct, is difficult to operationalize either for clinical or research purposes. According to DSM-III-R, schizophreniform disorder is descriptively identical to schizophrenia, differing only in duration of symptoms. This study suggests several features that, at initial examination, differentiate schizophreniform disorder from schizophrenia, such as higher DSM-III axis V ratings, lack of flattened affect, and better rapport with the examiner. The data suggest that when defined according to appropriate clinical criteria, schizophreniform disorder can be distinguished from either schizophrenia or affective disorder.