Most psychologists attribute mental illness to organic/neurochemical causes that can be treated with psychiatric medication, psychotherapy, lifestyle adjustments and other supportive measures; however, many of the causes of mental illness are still unknown. The battle between "nature" and "nurture" goes on as it has for years. Neuroscience and genetics are still unable to fully explain the effects of genetic inheritance and developmental environment.
Several medications like clozapine are available for treatment of psycotic disorders like confusion and defusion. You can find more information at http://www.drugdelivery.ca/s3392-s-CLOZARIL.aspx