Middle-ear disease and schizophrenia: case-control study.

BACKGROUND One hundred years ago psychiatrists thought that ear disease could cause insanity by irritation of the brain. Current understanding of the role of the temporal lobes in schizophrenia and their proximity to the middle ear supports this hypothesis. AIMS To establish the rate of middle-ear disease pre-dating the onset of schizophrenia. METHOD Eighty-four patients with schizophrenia were each matched to four non-psychiatric controls by age, gender and season of birth. History of ear disease was obtained from general practice records. Additional information on symptoms was collected for participants in the case group, who also had audiometry. RESULTS The odds ratio of recorded middle-ear disease pre-dating schizophrenia was 3.68 (95% CI 1.86-7.28). This excess was particularly marked on the left (OR=4.15, 95% CI 2.08-8.29). Auditory hallucinations were associated with middle-ear disease but not with hearing loss. CONCLUSIONS There is an association between middle-ear disease and schizophrenia which may have aetiological significance.