Paranoid schizophrenia, also called schizophrenia, paranoid type is a sub-type of schizophrenia as defined in the Diagnostic and Statistical Manual of Mental Disorders, DSM-IV code 295.30. It is the most common type of schizophrenia. Schizophrenia is defined as “a chronic mental illness in which a person loses touch with reality (psychosis)." Schizophrenia is divided into subtypes based on the “predominant symptomatology at the time of evaluation." The clinical picture is dominated by relatively stable, often persecutory, delusions, usually accompanied by hallucinations, particularly of the auditory variety (hearing voices), and perceptual disturbances. These symptoms can have a huge effect on functioning and can negatively affect a person’s quality of life. Paranoid schizophrenia is a lifelong illness, but with proper treatment, a person suffering from the illness can live a higher quality of life. Although paranoid schizophrenia is defined by those two symptoms, it is also defined by a lack of certain symptoms (negative symptoms). The following symptoms are not prominent: “disorganized speech, disorganized or catatonic behavior, or flat or inappropriate affect." Those symptoms are present in another form of schizophrenia, disorganized-type schizophrenia. The criteria for diagnosing paranoid schizophrenia must be present from at least one to six months. This helps to differentiate schizophrenia from other illnesses, such as bipolar disorder.