There has been and there is on-going research on treating schizophrenia with a broad spectrum antibiotic tetracycline, minocycline. It has proved beneficial in treating the symptoms of schizophrenia. You may want to check out an article in the Independent newspaper by Jeremy Laurance, type in minocycline and schizophrenia, You may also want to google the same words to see the range of research that is completed or on-going. Apparently a Japanese man presented to hospital with symptoms of schizophrenia and pneumonia when treated with minocycline for the chest infection his schizophrenia symptoms improved. there has been subsequent research in Israel and Pakistan and there is on-going research at the University of Manchester regarding the use of minocycline in treating schizophrenia.