That the source is a dated Australian Department of Health web page that does not advocate your position. How about primary medical evidence from peer-reviewed medical articles and studies? Moreover, comorbidity refers to a patient having a combination of illnesses. As to alcohol abuse and schizophrenia, the term comorbidity does not provide an inference that alcohol causes or directly worsens schizophrenia. At most, it means that alcohol abuse makes the life of a schizophrenia patient harder and treatment more difficult.