Ear disease and schizophrenia: a case-control study.
The rates of middle ear disease in 70 patients with schizophrenia from a defined catchment population were compared with the rates in 359 nonpsychiatric controls who were matched for age, sex and general practice. A relative risk (odds ratio) of middle ear disease in schizophrenia of 1.92 was found. This was raised to 2.29 when ear disease occurring after the onset of schizophrenia was excluded. Excluding aetiological factors such as brain damage or family history raised the odds ratio further to 2.50 and 2.71 respectively. The implications of these results are discussed, and it is suggested that middle ear disease may be an aetiological factor in some cases of schizophrenia.