Objective. To validate the Yoruba version of Family Burden Interview Schedule (Y-FBIS) for assessing the burden on caregivers of
persons with schizophrenia. Methods. Three hundred and sixty-eight dyads of persons with schizophrenia and their caregivers were
recruited from a psychiatric outpatient clinic. The (Y-FBIS) and the Yoruba version of the GHQ-12 (Y-GHQ-12) were applied to
the caregivers. Patients’ level of social functioning was assessed using the Global Assessment of Functioning scale. Results. All (368)
caregivers were used for tests of internal consistency, 180 for interrater reliability, and another 180 for test-retest reliability. Internal
consistency of the Y-FBIS was demonstrated by a significant Cronbach a of between 0.62 and 0.82 for each item. Concurrent
validity of the Y-FBIS was illustrated by its significant positive correlation with Y-GHQ-12 (r = 0.633 , P < 0.01). Split-half
reliability was 0.849. Intraclass correlation coefficient for the total score of Y-FBIS was 0.849 at 95% confidence interval. Test-retest
reliability of individual scales ranged from 0.780 to 0.874 and was 0.830 for total objective scale score. Convergent validity was
shown by the significant positive correlation (r = 0.83) between the objective burden score and subjective burden score of YFBIS.
ROC curve area was 0.981. Conclusion. The Y-FBIS is a valid, reliable, and sensitive instrument for assessing the burden on
caregivers of persons with schizophrenia in Nigeria.