Diagnostic and prognostic significance of Schneiderian first-rank symptoms: a 20-year longitudinal study of schizophrenia and bipolar disorder.

Objective: This research addresses the following questions: what is the prevalence and severity of first-rank symptoms (FRS) during an extended period of time in patients with schizophrenia and bipolar disorder with psychosis? Are the specific FRS listed in Diagnostic and Statistical Manual of Mental Disorders DSM, Third Edition, Revised/Fourth Edition Criterion A for schizophrenia diagnosis (a voice keeping a running commentary or voices conversing) more prevalent and severe in patients with schizophrenia than bipolar disorder with psychosis? Lastly, do FRS at index hospitalization in patients with schizophrenia predict the absence of later recovery?

Methods: This research follows a sample of patients with psychotic disorders who were evaluated at index hospitalization and then prospectively followed-up at 6 evaluations during next 20 years (n = 86). All patients were evaluated as part of a prospective research study designed to measure multiple factors of phenomenology, severity of illness, course of illness, prognosis, and global outcome.

Results: First-rank symptoms are not exclusive to schizophrenia; they also occur in some bipolar patients. However, they are more frequent and more severe in patients with schizophrenia than bipolar disorder. Schizophrenia patients with FRS during the acute phase are more likely to have poorer long-term outcome than schizophrenia patients who do not have FRS during the acute phase.

Conclusions: Our results indicate FRS at the acute phase are not a clinicopathologic correlate specific to schizophrenia. However, the presence and severity of any FRS and specifically of the 2 FRS associated with Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised/Fourth Edition Criterion A are more prevalent and more severe in patients with schizophrenia than patients with bipolar disorder.