Introduction: Schizophrenia (SC) and bipolar disorder (BP) are two of the most severe and incapacitating mental disorders. It has been questioned whether these two conditions designate distinct illnesses with different etiologies or whether they represent different ends of a clinical spectrum with a common etiology.
Materials and methods: This study compares social and clinical characteristics of 84 SC and 84 BP subjects from the Costa Rican Central Valley (CRCV) using information from the DIGS, FIGS and psychiatric records. Each of these subjects had a best estimate lifetime consensus diagnosis of either bipolar type I or SC.
Results: Subjects with SC differed from subjects with BP in social adjustment measures like marital and employment status, and number of children. Both groups were very similar in years of education, age of onset of their illness, history of other psychiatric co-morbidities, and treatment received.
Discussion: The high percentage of psychosis in the BP group (97.6%) may largely explain the similarities found between groups in their clinical characteristics.
Conclusion: The differences in social and functional decline support the original dichotomy described by Kraepelin based on chronicity and periodicity between these two psychotic disorders.